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It provides a quick reference to anatomical terms, body cavities, and much more.","noIndex":0,"noFollow":0},"content":"The human body is a beautiful and efficient system that everyone should know a little bit about. In order to study and talk about anatomy and physiology, though, you need to learn the language.\r\n\r\nYou have to have a solid grasp on the directional terms, the body cavities, and the overall organization of the organs and their division of labor.\r\n\r\nA familiarity with common Latin and Greek word roots will go a long way too.","description":"The human body is a beautiful and efficient system that everyone should know a little bit about. In order to study and talk about anatomy and physiology, though, you need to learn the language.\r\n\r\nYou have to have a solid grasp on the directional terms, the body cavities, and the overall organization of the organs and their division of labor.\r\n\r\nA familiarity with common Latin and Greek word roots will go a long way too.","blurb":"","authors":[{"authorId":11358,"name":"Erin Odya","slug":"erin-odya","description":" <p><b>Erin Odya</b> teaches Anatomy &#38; Physiology at Carmel High School in Carmel, Indiana, one of Indiana&#39;s top schools. She is also the author of <i>Anatomy &#38; Physiology For Dummies.</i> <p><b>Pat DuPree</b> taught anatomy/physiology, biology, medical terminology, and environmental science. 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","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/11358"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;anatomy&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781394153657&quot;]}]\" id=\"du-slot-6408f78f35520\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;anatomy&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781394153657&quot;]}]\" id=\"du-slot-6408f78f35bf5\"></div></div>"},"articleType":{"articleType":"Cheat Sheet","articleList":[{"articleId":0,"title":"","slug":null,"categoryList":[],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/"}}],"content":[{"title":"Anatomical terms","thumb":null,"image":null,"content":"<p>To speak the language, you first need to have a frame of reference. When comparing one part of the body to another, the position of the body matters. As a result, all descriptions are made assuming the body is in anatomical position: standing upright, facing forward, arms to the side with palms turned out, as shown in the figure below.</p>\n<div class=\"figure-container\"><figure id=\"attachment_297704\" aria-labelledby=\"figcaption_attachment_297704\" class=\"wp-caption alignnone\" style=\"width: 228px\"><img loading=\"lazy\" class=\"wp-image-297704 size-full\" src=\"https://www.dummies.com/wp-content/uploads/anatomy-illustration.jpg\" alt=\"Illustration of the female human anatomy\" width=\"218\" height=\"319\" /><figcaption id=\"figcaption_attachment_297704\" class=\"wp-caption-text\">©John Wiley &amp; Sons, Inc. <br />Body position for anatomical terms</figcaption></figure></div><div class=\"clearfix\"></div>\n<p>When you’re talking anatomy in a scientific way, everyday words such as <em>front, back, above,</em> and <em>below</em> just aren’t precise enough. Instead use the terms in the following list:</p>\n<ul>\n<li><strong>Anterior or ventral:</strong> Toward the front of the body</li>\n<li><strong>Posterior or dorsal:</strong> Toward the back of the body</li>\n<li><strong>Superior:</strong> A part above another part</li>\n<li><strong>Inferior:</strong> A part below another part</li>\n<li><strong>Medial:</strong> Toward the <em>midline</em> of the body</li>\n<li><strong>Lateral:</strong> Away from the midline of the body; toward the sides</li>\n<li><strong>Proximal:</strong> Toward the point of attachment to the body</li>\n<li><strong>Distal:</strong> Away from the point of attachment to the body</li>\n<li><strong>Deep:</strong> Toward the inside of the body</li>\n<li><strong>Superficial:</strong> Toward the outside of the body</li>\n<li><strong>Parietal:</strong> A membrane that covers an internal body wall</li>\n<li><strong>Visceral:</strong> A membrane that covers an organ</li>\n</ul>\n<p>Also remember that <em>right</em> and <em>left</em> are that of the patient, not the observer.</p>\n"},{"title":"Body cavities","thumb":null,"image":null,"content":"<p>Medical and crime shows have made body cavities all too familiar, and anatomically speaking, these spaces are very important, providing housing and protection for vital organs. The following list identifies the cavities of the human body.</p>\n<ul>\n<li><strong>Dorsal cavity:</strong> The space within the skull and vertebrae (backbone)\n<ul>\n<li><strong>Cranial cavity:</strong> Contains the brain</li>\n<li><strong>Spinal cavity:</strong> Contains the spinal cord, which is an extension of the brain</li>\n</ul>\n</li>\n<li><strong>Ventral cavity:</strong> Anterior portion of the torso; divided by the diaphragm into the thoracic cavity and abdominopelvic cavity<strong> </strong>\n<ul>\n<li><strong>Thoracic cavity:</strong> The chest or thorax; contains the heart, lungs, and their associated structures, as well as the esophagus and several glands\n<ul>\n<li><strong>Pleural cavities:</strong> Surround each lung</li>\n<li><strong>Pericardial cavity:</strong>  Contains the heart<br />\nThe pleural cavities flank the pericardial cavity</li>\n</ul>\n</li>\n</ul>\n</li>\n<li><strong>Abdominopelvic cavity: </strong>The portion of the ventral cavity below the diaphragm\n<ul>\n<li><strong>Abdominal cavity:</strong> Contains the stomach, liver, gallbladder, pancreas, spleen, small intestines, and most of the large intestine</li>\n<li><strong>Pelvic cavity:</strong> Contains the end of the large intestine, rectum, urinary bladder, and internal reproductive organs<br />\nThere is no obvious division between these two cavities</li>\n</ul>\n</li>\n</ul>\n"},{"title":"Organ systems","thumb":null,"image":null,"content":"<p>The body takes a divide-and-conquer approach to completing all of the tasks it must do to sustain life. Each body system has its own role to play, as shown in the table below.</p>\n<table width=\"615\">\n<tbody>\n<tr>\n<td><strong>System</strong></td>\n<td width=\"308\"><strong>What the System Includes</strong></td>\n<td width=\"264\"><strong>What the System Does</strong></td>\n</tr>\n<tr>\n<td width=\"167\">Integumentary</td>\n<td width=\"308\">Skin and its accessories</td>\n<td width=\"264\">Protects underlying tissues, regulates body temperature</td>\n</tr>\n<tr>\n<td>Skeletal</td>\n<td width=\"308\">Bones and connective tissues</td>\n<td width=\"264\">Provides framework, protects underlying soft tissues, produces blood cells</td>\n</tr>\n<tr>\n<td>Muscular</td>\n<td width=\"308\">Skeletal, smooth, and cardiac muscle</td>\n<td width=\"264\">Powers movement, maintains posture, generates heat</td>\n</tr>\n<tr>\n<td>Nervous</td>\n<td width=\"308\">Brain, spinal cord, nerves, sensory organs</td>\n<td width=\"264\">Communicates via impulse, integrates functions of other body systems</td>\n</tr>\n<tr>\n<td>Endocrine</td>\n<td width=\"308\">Pituitary, thyroid, parathyroid, and adrenal glands; pancreas; ovaries; and testes</td>\n<td width=\"264\">Communicates via hormones</td>\n</tr>\n<tr>\n<td>Cardiovascular</td>\n<td width=\"308\">Heart, blood vessels, and blood</td>\n<td width=\"264\">Transports materials throughout body</td>\n</tr>\n<tr>\n<td>Lymphatic</td>\n<td width=\"308\">Tonsils, spleen, thymus, lymph nodes, lymphatic vessels, and lymph</td>\n<td width=\"264\">Provides immunity, filters tissue fluid</td>\n</tr>\n<tr>\n<td>Digestive</td>\n<td width=\"308\">Mouth, esophagus, stomach, small and large intestines (alimentary canal), and accessory organs (including salivary glands, pancreas, liver, and gallbladder)</td>\n<td width=\"264\">Obtains nutrients from food</td>\n</tr>\n<tr>\n<td>Respiratory</td>\n<td width=\"308\">Nose and mouth, pharynx, larynx, trachea, bronchi, and lungs</td>\n<td width=\"264\">Performs gas exchange with blood (oxygen in, carbon dioxide out)</td>\n</tr>\n<tr>\n<td>Urinary</td>\n<td width=\"308\">Kidneys, ureters, bladder, and urethra</td>\n<td width=\"264\">Filters waste from the blood, retains water</td>\n</tr>\n<tr>\n<td>Reproductive</td>\n<td width=\"308\">Ovaries, uterine tubes, uterus, vagina, and vulva in females; testes, seminal vesicles, prostate, urethra, and penis in males</td>\n<td width=\"264\">Produces offspring</td>\n</tr>\n</tbody>\n</table>\n"},{"title":"Latin and Greek roots","thumb":null,"image":null,"content":"<p>Science, especially medicine, is permeated with Latin and Greek terms. Latin names are used for nearly every part of the body; and since the Greeks are the founders of modern medicine, Greek terms are common in medical terminology, as well.</p>\n<p>This table represents some common Latin and Greek roots used in anatomy and physiology:</p>\n<table width=\"602\">\n<tbody>\n<tr>\n<td><strong>English Form</strong></td>\n<td><strong>Meaning</strong></td>\n<td><strong>Example</strong></td>\n</tr>\n<tr>\n<td>angi(o)–</td>\n<td>vessel</td>\n<td>angiogram</td>\n</tr>\n<tr>\n<td>arthr(o)–</td>\n<td>joint</td>\n<td>arthritis</td>\n</tr>\n<tr>\n<td>bronch–</td>\n<td>air passage</td>\n<td>bronchitis</td>\n</tr>\n<tr>\n<td>calc(i)–</td>\n<td>calcium</td>\n<td>calcify</td>\n</tr>\n<tr>\n<td>card(i)–</td>\n<td>heart</td>\n<td>cardiovascular</td>\n</tr>\n<tr>\n<td>cili–</td>\n<td>small hair</td>\n<td>cilia</td>\n</tr>\n<tr>\n<td>corp–</td>\n<td>body</td>\n<td>corpus luteum</td>\n</tr>\n<tr>\n<td>crani–</td>\n<td>skull</td>\n<td>cranium</td>\n</tr>\n<tr>\n<td>cut(an)–</td>\n<td>skin</td>\n<td>cutaneous</td>\n</tr>\n<tr>\n<td>gastr(o)–</td>\n<td>stomach, belly</td>\n<td>gastric</td>\n</tr>\n<tr>\n<td>gluc(o)–</td>\n<td>sweet, sugar</td>\n<td>glucosa</td>\n</tr>\n<tr>\n<td>hemat(o)–</td>\n<td>blood</td>\n<td>hematology</td>\n</tr>\n<tr>\n<td>hist(o)–</td>\n<td>webbing (tissue)</td>\n<td>histology</td>\n</tr>\n<tr>\n<td>hyster(o)–</td>\n<td>womb</td>\n<td>hysterectomy</td>\n</tr>\n<tr>\n<td>lig–</td>\n<td>to bind</td>\n<td>ligament</td>\n</tr>\n<tr>\n<td>osteo–</td>\n<td>bone</td>\n<td>osteoblast</td>\n</tr>\n<tr>\n<td>pleur–</td>\n<td>side, rib</td>\n<td>pleural cavity</td>\n</tr>\n<tr>\n<td>pulm(o)–</td>\n<td>lung</td>\n<td>pulmonary</td>\n</tr>\n<tr>\n<td>ren–</td>\n<td>kidney</td>\n<td>renal</td>\n</tr>\n<tr>\n<td>squam–</td>\n<td>scale, flat</td>\n<td>squamous</td>\n</tr>\n<tr>\n<td>thorac–</td>\n<td>chest</td>\n<td>thoracic</td>\n</tr>\n<tr>\n<td>vasc–</td>\n<td>vessel</td>\n<td>vascular</td>\n</tr>\n</tbody>\n</table>\n"}],"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Advance","lifeExpectancy":"Five years","lifeExpectancySetFrom":"2023-03-08T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":297702},{"headers":{"creationTime":"2016-03-26T17:39:19+00:00","modifiedTime":"2023-02-15T14:52:37+00:00","timestamp":"2023-02-15T15:01:02+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Environmental Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33763"},"slug":"environmental-science","categoryId":33763}],"title":"What Causes Earthquakes?","strippedTitle":"what causes earthquakes?","slug":"what-are-earthquakes","canonicalUrl":"","seo":{"metaDescription":"This article answers your questions about earthquakes, including what causes them and how they are measured.","noIndex":0,"noFollow":0},"content":"An earthquake is the sometimes violent shaking of the ground caused by movements of Earth's tectonic plates. Most earthquakes occur along fault lines, which is where two tectonic plates come together.\r\n\r\n[caption id=\"attachment_297287\" align=\"alignnone\" width=\"630\"]<img class=\"size-full wp-image-297287\" src=\"https://www.dummies.com/wp-content/uploads/seismograph-illustration-adobeStock_109721942.jpg\" alt=\"\" width=\"630\" height=\"347\" /> ©Andrey VP / Adobe Stock[/caption]\r\n\r\nEarthquakes strike suddenly and violently and can occur at any time, day or night, throughout the year. Smaller earthquakes might crack some windows and shake products off store shelves, but larger earthquakes can cause death and massive destruction, devastating communities and debilitating local economies.\r\n<h2 id=\"tab1\" >A tectonic shift</h2>\r\nEarthquakes occur when large sections of the Earths' crust — called <i>tectonic </i>plates — shift. There are seven primary tectonic plates (African, Antarctic, Eurasian, Indo-Australian, North American, Pacific, and South American) and a number of smaller, secondary and tertiary plates. Because of underlying movement in the Earth's mantle, these plates can shift.\r\n\r\nThis shifting of one plate causes it to rub against or push under or over an adjacent plate. The place where two plates meet is called a <i>fault line,</i> and it's at these fault lines that earthquakes occur.\r\n\r\nEarthquakes are often followed by smaller earthquakes called <i>aftershocks,</i> which can occur over days or weeks as the plates settle into equilibrium.\r\n<p class=\"TechnicalStuff\">In the United States, California experiences damaging earthquakes most often, but Alaska has the greatest number of large earthquakes. They occur mostly in uninhabited areas, though, and so don't cause as much damage.</p>\r\n\r\n<h2 id=\"tab2\" >What can earthquakes do?</h2>\r\nThe violent ground-shaking of earthquakes by itself can cause damage to homes, roads, and bridges; shake products off shelves; and lead to injuries and death, but earthquakes can also lead to other natural disasters:\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\"><b>Avalanches and landslides:</b> Earthquakes can shake snow, soil, and rock right off a sloped surface. Landslides have been a particular problem in California, where a number of mountainside homes have ended up in the Pacific Ocean because of them.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><b>Surface faulting:</b> Surface faulting is a change in the relative positions of things on opposite sides of a fault line. For instance, a straight section of railroad track that runs across a fault line might have a nasty curve in it after an earthquake, rendering it useless for train travel.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><b>Tsunamis:</b> Tsunamis are a series of waves that are caused by the sudden displacement of large amounts of ocean water, usually because of underwater earthquakes. When tsunamis hit land, they can knock over buildings, wash away cars, and cause massive flooding. The most massive tsunamis can reach heights of well over 500 feet.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><b>Liquefaction:</b> Liquefaction occurs when water-logged soil acts like a liquid and causes sections of ground to sink or slide. As well as damage to roads and buildings, liquefaction can lead to flash floods.</p>\r\n</li>\r\n</ul>\r\n<h2 id=\"tab3\" >How are earthquakes measured?</h2>\r\n<i>Seismometers </i>and <i>seismographs</i> sense and record movements in the Earth's surface, showing both the intensity and duration of earthquakes and other tremors. <i>Seismologists</i> then use this information to rate the earthquake on the Richter scale.\r\n\r\nThe Richter scale was developed in 1935 by Charles Richter to show the amount of energy released during an earthquake. It was originally intended not as an absolute measure of individual quakes but as a way to compare the relative strengths of different earthquakes. Though Richter measurements are generally thought of as being between 0 and 10, there are theoretically no limits to the scale in either direction.\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\">Earthquakes measuring <b>less than 4.0 magnitude</b> occur in small areas and might not even be noticed, much less cause any serious damage.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Earthquakes measuring <b>4.0–4.9 magnitude</b> cover a larger area. They are felt, but damage is light.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">You start to see some damage with a <b>5.0-magnitude earthquake</b>, starting with poorly constructed buildings.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Higher up on the Richter scale, you see greater damage over a greater area.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">The largest recorded earthquake was the <b>9.5-magnitude</b> Great Chilean Earthquake of 1960. This quake spawned numerous tsunamis that caused damage as far away as Hawaii, Japan, and the Philippines.</p>\r\n</li>\r\n</ul>","description":"An earthquake is the sometimes violent shaking of the ground caused by movements of Earth's tectonic plates. Most earthquakes occur along fault lines, which is where two tectonic plates come together.\r\n\r\n[caption id=\"attachment_297287\" align=\"alignnone\" width=\"630\"]<img class=\"size-full wp-image-297287\" src=\"https://www.dummies.com/wp-content/uploads/seismograph-illustration-adobeStock_109721942.jpg\" alt=\"\" width=\"630\" height=\"347\" /> ©Andrey VP / Adobe Stock[/caption]\r\n\r\nEarthquakes strike suddenly and violently and can occur at any time, day or night, throughout the year. Smaller earthquakes might crack some windows and shake products off store shelves, but larger earthquakes can cause death and massive destruction, devastating communities and debilitating local economies.\r\n<h2 id=\"tab1\" >A tectonic shift</h2>\r\nEarthquakes occur when large sections of the Earths' crust — called <i>tectonic </i>plates — shift. There are seven primary tectonic plates (African, Antarctic, Eurasian, Indo-Australian, North American, Pacific, and South American) and a number of smaller, secondary and tertiary plates. Because of underlying movement in the Earth's mantle, these plates can shift.\r\n\r\nThis shifting of one plate causes it to rub against or push under or over an adjacent plate. The place where two plates meet is called a <i>fault line,</i> and it's at these fault lines that earthquakes occur.\r\n\r\nEarthquakes are often followed by smaller earthquakes called <i>aftershocks,</i> which can occur over days or weeks as the plates settle into equilibrium.\r\n<p class=\"TechnicalStuff\">In the United States, California experiences damaging earthquakes most often, but Alaska has the greatest number of large earthquakes. They occur mostly in uninhabited areas, though, and so don't cause as much damage.</p>\r\n\r\n<h2 id=\"tab2\" >What can earthquakes do?</h2>\r\nThe violent ground-shaking of earthquakes by itself can cause damage to homes, roads, and bridges; shake products off shelves; and lead to injuries and death, but earthquakes can also lead to other natural disasters:\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\"><b>Avalanches and landslides:</b> Earthquakes can shake snow, soil, and rock right off a sloped surface. Landslides have been a particular problem in California, where a number of mountainside homes have ended up in the Pacific Ocean because of them.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><b>Surface faulting:</b> Surface faulting is a change in the relative positions of things on opposite sides of a fault line. For instance, a straight section of railroad track that runs across a fault line might have a nasty curve in it after an earthquake, rendering it useless for train travel.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><b>Tsunamis:</b> Tsunamis are a series of waves that are caused by the sudden displacement of large amounts of ocean water, usually because of underwater earthquakes. When tsunamis hit land, they can knock over buildings, wash away cars, and cause massive flooding. The most massive tsunamis can reach heights of well over 500 feet.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\"><b>Liquefaction:</b> Liquefaction occurs when water-logged soil acts like a liquid and causes sections of ground to sink or slide. As well as damage to roads and buildings, liquefaction can lead to flash floods.</p>\r\n</li>\r\n</ul>\r\n<h2 id=\"tab3\" >How are earthquakes measured?</h2>\r\n<i>Seismometers </i>and <i>seismographs</i> sense and record movements in the Earth's surface, showing both the intensity and duration of earthquakes and other tremors. <i>Seismologists</i> then use this information to rate the earthquake on the Richter scale.\r\n\r\nThe Richter scale was developed in 1935 by Charles Richter to show the amount of energy released during an earthquake. It was originally intended not as an absolute measure of individual quakes but as a way to compare the relative strengths of different earthquakes. Though Richter measurements are generally thought of as being between 0 and 10, there are theoretically no limits to the scale in either direction.\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\">Earthquakes measuring <b>less than 4.0 magnitude</b> occur in small areas and might not even be noticed, much less cause any serious damage.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Earthquakes measuring <b>4.0–4.9 magnitude</b> cover a larger area. They are felt, but damage is light.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">You start to see some damage with a <b>5.0-magnitude earthquake</b>, starting with poorly constructed buildings.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Higher up on the Richter scale, you see greater damage over a greater area.</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">The largest recorded earthquake was the <b>9.5-magnitude</b> Great Chilean Earthquake of 1960. This quake spawned numerous tsunamis that caused damage as far away as Hawaii, Japan, and the Philippines.</p>\r\n</li>\r\n</ul>","blurb":"","authors":[{"authorId":9772,"name":"Andrew Hollandbeck","slug":"andrew-hollandbeck","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9772"}}],"primaryCategoryTaxonomy":{"categoryId":33763,"title":"Environmental Science","slug":"environmental-science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33763"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[{"label":"A tectonic shift","target":"#tab1"},{"label":"What can earthquakes do?","target":"#tab2"},{"label":"How are earthquakes measured?","target":"#tab3"}],"relatedArticles":{"fromBook":[],"fromCategory":[{"articleId":292097,"title":"Find New Ways to Go Green this Earth Day","slug":"this-earth-day-find-new-ways-to-go-green","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/292097"}},{"articleId":291362,"title":"Climate Change For Dummies Cheat Sheet","slug":"climate-change-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/291362"}},{"articleId":284309,"title":"Check Out the Bones on Those Osteichthyes!","slug":"check-out-the-bones-on-those-osteichthyes","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/284309"}},{"articleId":284296,"title":"Elasmobranchii: Sharks, Skates, and Rays","slug":"elasmobranchii-sharks-skates-and-rays","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/284296"}},{"articleId":284288,"title":"Cephalopods: Head and Tentacles Above the Rest","slug":"cephalopods-head-and-tentacles-above-the-rest","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/284288"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":0,"slug":null,"isbn":null,"categoryList":null,"amazon":null,"image":null,"title":null,"testBankPinActivationLink":null,"bookOutOfPrint":false,"authorsInfo":null,"authors":null,"_links":null},"collections":[],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;environmental-science&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[null]}]\" id=\"du-slot-63ecf3ae9b9b8\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;environmental-science&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[null]}]\" id=\"du-slot-63ecf3ae9c3f5\"></div></div>"},"articleType":{"articleType":"Articles","articleList":null,"content":null,"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Explore","lifeExpectancy":"Five years","lifeExpectancySetFrom":"2023-02-15T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":175763},{"headers":{"creationTime":"2016-03-26T18:14:29+00:00","modifiedTime":"2023-02-07T16:00:49+00:00","timestamp":"2023-02-07T18:01:03+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Physics","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33769"},"slug":"physics","categoryId":33769}],"title":"String Theory and The Hierarchy Problem in Physics","strippedTitle":"string theory and the hierarchy problem in physics","slug":"string-theory-and-the-hierarchy-problem-in-physics","canonicalUrl":"","seo":{"metaDescription":"Many physicists feel that string theory will ultimately be successful at resolving the hierarchy problem of the Standard Model of particle physics. Although it ","noIndex":0,"noFollow":0},"content":"Many physicists feel that string theory will ultimately be successful at resolving the hierarchy problem of the Standard Model of particle physics. Although it is an astounding success, the Standard Model hasn’t answered every question that physics hands to it. One of the major questions that remains is the <em>hierarchy problem</em>, which seeks an explanation for the diverse values that the Standard Model lets physicists work with.\r\n\r\nFor example, if you count the theoretical Higgs boson (and both types of W bosons), the Standard Model of particle physics has 18 elementary particles. The masses of these particles aren’t predicted by the Standard Model. Physicists had to find these by experiment and plug them into the equations to get everything to work out right.\r\n\r\nYou notice three families of particles among the fermions, which seems like a lot of unnecessary duplication. If we already have an electron, why does nature need to have a muon that’s 200 times as heavy? Why do we have so many types of quarks?\r\n\r\nBeyond that, when you look at the energy scales associated with the quantum field theories of the Standard Model, as shown in this figure, even more questions may occur to you. Why is there a gap of 16 orders of magnitude (16 zeroes!) between the intensity of the Planck scale energy and the weak scale?\r\n\r\n[caption id=\"attachment_16789\" align=\"aligncenter\" width=\"226\"]<img src=\"https://www.dummies.com/wp-content/uploads/315460.image0.jpg\" alt=\"\" width=\"226\" height=\"400\" class=\"size-full wp-image-16789\" /> Credit: � 2005 by Lisa Randall, reprinted by permission of HarperCollins Publishers.[/caption]\r\n\r\nAt the bottom of this scale is the <em>vacuum energy,</em> which is the energy generated by all the strange quantum behavior in empty space — virtual particles exploding into existence and quantum fields fluctuating wildly due to the uncertainty principle.\r\n\r\nThe hierarchy problem occurs because the fundamental parameters of the Standard Model don’t reveal anything about these scales of energy. Just as physicists have to put the particles and their masses into the theory by hand, so too have they had to construct the energy scales by hand. Fundamental principles of physics don’t tell scientists how to transition smoothly from talking about the weak scale to talking about the Planck scale.\r\n\r\nTrying to understand the “gap” between the weak scale and the Planck scale is one of the major motivating factors behind trying to search for a quantum gravity theory in general, and string theory in particular.\r\n\r\nMany physicists would like a single theory that could be applied at all scales, without the need for renormalization (the mathematical process of removing infinities), or at least to understand what properties of nature determine the rules that work for different scales. Others are perfectly happy with renormalization, which has been a major tool of physics for nearly 40 years and works in virtually every problem that physicists run into.","description":"Many physicists feel that string theory will ultimately be successful at resolving the hierarchy problem of the Standard Model of particle physics. Although it is an astounding success, the Standard Model hasn’t answered every question that physics hands to it. One of the major questions that remains is the <em>hierarchy problem</em>, which seeks an explanation for the diverse values that the Standard Model lets physicists work with.\r\n\r\nFor example, if you count the theoretical Higgs boson (and both types of W bosons), the Standard Model of particle physics has 18 elementary particles. The masses of these particles aren’t predicted by the Standard Model. Physicists had to find these by experiment and plug them into the equations to get everything to work out right.\r\n\r\nYou notice three families of particles among the fermions, which seems like a lot of unnecessary duplication. If we already have an electron, why does nature need to have a muon that’s 200 times as heavy? Why do we have so many types of quarks?\r\n\r\nBeyond that, when you look at the energy scales associated with the quantum field theories of the Standard Model, as shown in this figure, even more questions may occur to you. Why is there a gap of 16 orders of magnitude (16 zeroes!) between the intensity of the Planck scale energy and the weak scale?\r\n\r\n[caption id=\"attachment_16789\" align=\"aligncenter\" width=\"226\"]<img src=\"https://www.dummies.com/wp-content/uploads/315460.image0.jpg\" alt=\"\" width=\"226\" height=\"400\" class=\"size-full wp-image-16789\" /> Credit: � 2005 by Lisa Randall, reprinted by permission of HarperCollins Publishers.[/caption]\r\n\r\nAt the bottom of this scale is the <em>vacuum energy,</em> which is the energy generated by all the strange quantum behavior in empty space — virtual particles exploding into existence and quantum fields fluctuating wildly due to the uncertainty principle.\r\n\r\nThe hierarchy problem occurs because the fundamental parameters of the Standard Model don’t reveal anything about these scales of energy. Just as physicists have to put the particles and their masses into the theory by hand, so too have they had to construct the energy scales by hand. Fundamental principles of physics don’t tell scientists how to transition smoothly from talking about the weak scale to talking about the Planck scale.\r\n\r\nTrying to understand the “gap” between the weak scale and the Planck scale is one of the major motivating factors behind trying to search for a quantum gravity theory in general, and string theory in particular.\r\n\r\nMany physicists would like a single theory that could be applied at all scales, without the need for renormalization (the mathematical process of removing infinities), or at least to understand what properties of nature determine the rules that work for different scales. Others are perfectly happy with renormalization, which has been a major tool of physics for nearly 40 years and works in virtually every problem that physicists run into.","blurb":"","authors":[{"authorId":9499,"name":"Andrew Zimmerman Jones","slug":"andrew-zimmerman-jones","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9499"}},{"authorId":9500,"name":"Daniel Robbins","slug":"daniel-robbins","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9500"}}],"primaryCategoryTaxonomy":{"categoryId":33769,"title":"Physics","slug":"physics","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33769"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[],"relatedArticles":{"fromBook":[{"articleId":209405,"title":"String Theory For Dummies Cheat Sheet","slug":"string-theory-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/209405"}},{"articleId":178042,"title":"More Dimensions Make String Theory Work","slug":"more-dimensions-make-string-theory-work","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/178042"}}],"fromCategory":[{"articleId":209405,"title":"String Theory For Dummies Cheat Sheet","slug":"string-theory-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/209405"}},{"articleId":209012,"title":"Physics II For Dummies Cheat Sheet","slug":"physics-ii-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/209012"}},{"articleId":208592,"title":"Thermodynamics For Dummies Cheat Sheet","slug":"thermodynamics-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208592"}},{"articleId":208578,"title":"Optics For Dummies Cheat Sheet","slug":"optics-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208578"}},{"articleId":208460,"title":"Physics I For Dummies Cheat Sheet","slug":"physics-i-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208460"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":294138,"slug":"string-theory-for-dummies-2","isbn":"9781119888970","categoryList":["academics-the-arts","science","quantum-physics"],"amazon":{"default":"https://www.amazon.com/gp/product/1119888972/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/1119888972/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/1119888972-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/1119888972/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/1119888972/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":"https://www.dummies.com/wp-content/uploads/string-theory-for-dummies-cover-9781119888970-203x255.jpg","width":203,"height":255},"title":"String Theory For Dummies","testBankPinActivationLink":"","bookOutOfPrint":true,"authorsInfo":"","authors":[{"authorId":9499,"name":"Andrew Zimmerman Jones","slug":"andrew-zimmerman-jones","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9499"}},{"authorId":35165,"name":"Alessandro Sfrondrini","slug":"alessandro-sfrondrini","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/35165"}},{"authorId":35186,"name":"Alessandro Sfondrini","slug":"alessandro-sfondrini","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/35186"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;physics&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119888970&quot;]}]\" id=\"du-slot-63e291df91643\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;physics&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119888970&quot;]}]\" id=\"du-slot-63e291df91cb2\"></div></div>"},"articleType":{"articleType":"Articles","articleList":null,"content":null,"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Advance","lifeExpectancy":"One year","lifeExpectancySetFrom":"2023-02-07T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":178179},{"headers":{"creationTime":"2016-03-27T16:56:16+00:00","modifiedTime":"2023-01-09T20:39:46+00:00","timestamp":"2023-01-09T21:01:02+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Chemistry","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33762"},"slug":"chemistry","categoryId":33762}],"title":"Organic Chemistry II For Dummies Cheat Sheet","strippedTitle":"organic chemistry ii for dummies cheat sheet","slug":"organic-chemistry-ii-for-dummies-cheat-sheet","canonicalUrl":"","seo":{"metaDescription":"This Organic Chemistry II Cheat Sheet includes tips for doing well in your class and for preparing for an exam.","noIndex":0,"noFollow":0},"content":"Organic Chemistry II is one of the toughest courses you can take. Surviving isn’t easy — you probably know that from your Organic Chemistry I class. Preparation is key: If you study the <a href=\"https://www.dummies.com/education/science/biology/the-basics-of-organic-chemistry/\" target=\"_blank\" rel=\"noopener\">basics of organic chemistry</a> the right way, prepare for your tests, and know your aromatic systems, you’re off to a great start!","description":"Organic Chemistry II is one of the toughest courses you can take. Surviving isn’t easy — you probably know that from your Organic Chemistry I class. Preparation is key: If you study the <a href=\"https://www.dummies.com/education/science/biology/the-basics-of-organic-chemistry/\" target=\"_blank\" rel=\"noopener\">basics of organic chemistry</a> the right way, prepare for your tests, and know your aromatic systems, you’re off to a great start!","blurb":"","authors":[{"authorId":9159,"name":"John T. Moore","slug":"john-t-moore","description":" <p><b>John T. Moore, EdD,</b> is Regents Professor of Chemistry at Stephen F. Austin State University in Nacogdoches, Texas. He is the author of <i>Chemistry For Dummies.</i> <b>Richard H. Langley, PhD,</b> teaches chemistry at Stephen F. Austin State University. Langley and Moore are coauthors of <i>Biochemistry For Dummies.</i> ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9159"}},{"authorId":9452,"name":"Richard H. Langley","slug":"richard-h-langley","description":" <p><b>Heather Hattori</b> has taught both high school and college level chemistry during her 30+ years in education.</p> <p><b>Richard H. Langley, PhD,</b> is on the faculty of Stephen F. Austin State University in Nacogdoches,Texas, where he teaches chemistry. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9452"}}],"primaryCategoryTaxonomy":{"categoryId":33762,"title":"Chemistry","slug":"chemistry","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33762"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[],"relatedArticles":{"fromBook":[{"articleId":192496,"title":"Organic Chemistry II: Directing Groups for Aromatic Systems","slug":"organic-chemistry-ii-directing-groups-for-aromatic-systems","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192496"}},{"articleId":192491,"title":"Study Tips for Organic Chemistry II","slug":"study-tips-for-organic-chemistry-ii","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192491"}},{"articleId":192486,"title":"Tips for Taking an Organic Chemistry II Exam","slug":"tips-for-taking-an-organic-chemistry-ii-exam","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192486"}}],"fromCategory":[{"articleId":295575,"title":"Chemistry All-in-One For Dummies Cheat Sheet","slug":"chemistry-all-in-one-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/295575"}},{"articleId":253707,"title":"How to Make Unit Conversions","slug":"make-unit-conversions","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/253707"}},{"articleId":251836,"title":"How to Convert between Units Using Conversion Factors","slug":"convert-units-using-conversion-factors","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251836"}},{"articleId":251010,"title":"How to Build Derived Units from Base Units","slug":"build-derived-units-base-units","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251010"}},{"articleId":251005,"title":"How to Do Arithmetic with Significant Figures","slug":"arithmetic-significant-figures","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251005"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":282436,"slug":"organic-chemistry-ii-for-dummies","isbn":"9781119985174","categoryList":["academics-the-arts","science","chemistry"],"amazon":{"default":"https://www.amazon.com/gp/product/111998517X/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/111998517X/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/111998517X-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/111998517X/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/111998517X/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":"https://www.dummies.com/wp-content/uploads/organic-chemistry-ii-for-dummies-cover-9781119985174-203x255.jpg","width":203,"height":255},"title":"Organic Chemistry II For Dummies, 2nd Edition","testBankPinActivationLink":"","bookOutOfPrint":true,"authorsInfo":"<p><p><b><b data-author-id=\"9159\">John T. Moore</b>, EdD,</b> is Regents Professor of Chemistry at Stephen F. Austin State University in Nacogdoches, Texas. He is the author of <i>Chemistry For Dummies.</i> <b>Richard H. Langley, PhD,</b> teaches chemistry at Stephen F. Austin State University. Langley and Moore are coauthors of <i>Biochemistry For Dummies.</i> <p><b>Heather Hattori</b> has taught both high school and college level chemistry during her 30+ years in education.</p> <p><b><b data-author-id=\"9452\">Richard H. Langley</b>, PhD,</b> is on the faculty of Stephen F. Austin State University in Nacogdoches,Texas, where he teaches chemistry.</p>","authors":[{"authorId":9159,"name":"John T. Moore","slug":"john-t-moore","description":" <p><b>John T. Moore, EdD,</b> is Regents Professor of Chemistry at Stephen F. Austin State University in Nacogdoches, Texas. He is the author of <i>Chemistry For Dummies.</i> <b>Richard H. Langley, PhD,</b> teaches chemistry at Stephen F. Austin State University. Langley and Moore are coauthors of <i>Biochemistry For Dummies.</i> ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9159"}},{"authorId":9452,"name":"Richard H. Langley","slug":"richard-h-langley","description":" <p><b>Heather Hattori</b> has taught both high school and college level chemistry during her 30+ years in education.</p> <p><b>Richard H. Langley, PhD,</b> is on the faculty of Stephen F. Austin State University in Nacogdoches,Texas, where he teaches chemistry. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9452"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;chemistry&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119985174&quot;]}]\" id=\"du-slot-63bc808ec13d6\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;chemistry&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119985174&quot;]}]\" id=\"du-slot-63bc808ec24fc\"></div></div>"},"articleType":{"articleType":"Cheat Sheet","articleList":[{"articleId":192491,"title":"Study Tips for Organic Chemistry II","slug":"study-tips-for-organic-chemistry-ii","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192491"}},{"articleId":192486,"title":"Tips for Taking an Organic Chemistry II Exam","slug":"tips-for-taking-an-organic-chemistry-ii-exam","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192486"}},{"articleId":192496,"title":"Organic Chemistry II: Directing Groups for Aromatic Systems","slug":"organic-chemistry-ii-directing-groups-for-aromatic-systems","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192496"}}],"content":[{"title":"Study tips for organic chemistry","thumb":null,"image":null,"content":"<p>Organic Chemistry II doesn’t have to be as difficult as you think. Follow these study tips to improve your understanding of organic chemistry, from carbon atom bonds to unnamed reactions, and everything in between:</p>\n<ul class=\"level-one\">\n<li>\n<p class=\"first-para\">Don’t simply memorize concepts, learn the concepts by working exercises.</p>\n</li>\n<li>\n<p class=\"first-para\">Keep up with the material by studying Organic Chemistry II a minimum of six days a week.</p>\n</li>\n<li>\n<p class=\"first-para\">Buy and use a model kit.</p>\n</li>\n<li>\n<p class=\"first-para\">For each reaction you study, know where and why the electrons are moving.</p>\n</li>\n<li>\n<p class=\"first-para\">Learn those named (and unnamed) reactions.</p>\n</li>\n<li>\n<p class=\"first-para\">Use other resources in addition to your textbook (like the excellent <i>Organic Chemistry II For Dummies, </i>written by John T. Moore and Richard H. Langley and published by Wiley).</p>\n</li>\n<li>\n<p class=\"first-para\">Read ahead in your textbook before class.</p>\n</li>\n<li>\n<p class=\"first-para\">Take really good class notes and recopy them as soon as possible.</p>\n</li>\n<li>\n<p class=\"first-para\">If you need help, ask questions.</p>\n</li>\n</ul>\n"},{"title":"Tips for taking an Organic Chemistry II exam","thumb":null,"image":null,"content":"<p>Taking an Organic Chemistry II test has a completely deserved reputation for being tough. Make life easier by following these tips before you take your next organic chemistry exam:</p>\n<ul class=\"level-one\">\n<li>\n<p class=\"first-para\">Remember that the carbon atom forms four bonds.</p>\n</li>\n<li>\n<p class=\"first-para\">Don’t cram the night (or even a week) before a test.</p>\n</li>\n<li>\n<p class=\"first-para\">Attend class religiously.</p>\n</li>\n<li>\n<p class=\"first-para\">Correct the mistakes you made on previous exams and don’t make the same mistakes again.</p>\n</li>\n<li>\n<p class=\"first-para\">Assign formal charges and use them to help decide most probable structure, sites for nucleophilic/electrophilic attack, and so on.</p>\n</li>\n<li>\n<p class=\"first-para\">When writing an organic reaction, be sure you don’t lose any carbon atoms.</p>\n</li>\n<li>\n<p class=\"first-para\">Relax and get enough sleep the night before an exam.</p>\n</li>\n<li>\n<p class=\"first-para\">Include E/Z, R/S, and cis/trans prefixes when naming organic structures.</p>\n</li>\n<li>\n<p class=\"first-para\">Think of spectroscopic data, especially NMR, as puzzle pieces and try to fit them together.</p>\n</li>\n<li>\n<p class=\"first-para\">Work problem sets and practice exams twice.</p>\n</li>\n<li>\n<p class=\"first-para\">If you find you’ve drawn a compound in which a carbon doesn’t have four bonds, go back to the beginning of this list.</p>\n</li>\n</ul>\n"},{"title":"Organic Chemistry II: Directing groups for aromatic systems","thumb":null,"image":null,"content":"<p>In an Organic Chemistry II class you often add groups to aromatic systems. If you’re wondering where the substitution will take place, check out this table for some guidelines. When using this table, remember two things:</p>\n<ul class=\"level-one\">\n<li>\n<p class=\"first-para\"><i>O-p</i>-directors always beat <i>m</i>-directors.</p>\n</li>\n<li>\n<p class=\"first-para\">Strong activators always beat weak activators.</p>\n</li>\n</ul>\n<p style=\"text-align: center;\"><strong>Classification of Various Aromatic Substituents</strong></p>\n<table>\n<tbody>\n<tr>\n<th>Ortho-Para-Directors</th>\n</tr>\n<tr>\n<td>Very Strong Activators</td>\n<td>-NH<sub>2</sub>, -NHR, -NR<sub>2</sub>, -OH,<br />\n-O<sup>–</sup></td>\n</tr>\n<tr>\n<td>Moderate Activators</td>\n<td>-OR, -NH-CO-R, -O-CO-R</td>\n</tr>\n<tr>\n<td>Weak Activators</td>\n<td>-R, -C<sub>6</sub>H<sub>5</sub></td>\n</tr>\n<tr>\n<td>Mild Deactivators</td>\n<td>-F, -Cl, -Br, -I</td>\n</tr>\n<tr>\n<th>Meta-Directors</th>\n</tr>\n<tr>\n<td>Very Strong Deactivators</td>\n<td>-N<sup>+</sup>R<sub>3</sub>, -NO<sub>2</sub>, -CN,<br />\n-CCl<sub>3</sub>, -CF<sub>3</sub></td>\n</tr>\n<tr>\n<td>Moderate to Mild Deactivators</td>\n<td>-CN, -SO<sub>3</sub>H, -CO-R, -COOH, -COOR, -CONH<sub>2</sub>,<br />\n-N<sup>+</sup>H<sub>3</sub></td>\n</tr>\n</tbody>\n</table>\n"}],"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Advance","lifeExpectancy":"Five years","lifeExpectancySetFrom":"2023-01-09T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":209020},{"headers":{"creationTime":"2016-03-26T21:46:40+00:00","modifiedTime":"2023-01-05T17:02:21+00:00","timestamp":"2023-01-05T18:01:03+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Environmental Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33763"},"slug":"environmental-science","categoryId":33763}],"title":"How Does Nuclear Fusion Work?","strippedTitle":"how does nuclear fusion work?","slug":"nuclear-fusion-the-hope-for-our-energy-future","canonicalUrl":"","seo":{"metaDescription":"Here's an easy-to-understand explanation of nuclear fusion, how it differs from fission, and how fusion might be our clean energy solution.","noIndex":0,"noFollow":0},"content":"Nuclear fusion is essentially the opposite of nuclear fission. In fission, a heavy nucleus is split into smaller nuclei. With fusion, lighter nuclei are fused into a heavier nucleus.\r\n\r\n[caption id=\"attachment_296438\" align=\"alignnone\" width=\"630\"]<img class=\"size-full wp-image-296438\" src=\"https://www.dummies.com/wp-content/uploads/fusion-diagram-adobestock_392113805.jpg\" alt=\"Diagram of nuclear fusion reaction\" width=\"630\" height=\"378\" /> ©Uday / Adobe Stock[/caption]\r\n\r\nThe fusion process is the reaction that powers the sun. On the sun, in a series of nuclear reactions, four isotopes of hydrogen-1 are fused into a helium-4 with the release of a tremendous amount of energy.\r\n\r\nHere on earth, two other isotopes of hydrogen are used: H-2, called deuterium, and H-3, called tritium. Deuterium is a minor isotope of hydrogen, but it’s still relatively abundant. Tritium doesn’t occur naturally, but it can easily be produced by bombarding deuterium with a neutron.\r\n\r\nThe fusion reaction is shown in the following equation:\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/167931.image0.png\" alt=\"image0.png\" width=\"133\" height=\"25\" />\r\n<h2 id=\"tab1\" >Major breakthrough in 2022</h2>\r\nIn December 2022, scientists at the U.S. National Ignition Facility in Livermore, California, achieved a major breakthrough in nuclear fusion research: <em>energy gain</em>. Energy gain, also known in this context as <em>ignition</em>, means that they were able to create a fusion reaction that released more energy than they put in by their lab's gigantic high-powered lasers.\r\n\r\nThe scientists said they proved nuclear fusion can work on Earth, but we are still many years from being able to use it in power plants. Yet, scientists are optimistic that controlled fusion power will be achieved. The rewards are great — an unlimited source of clean energy.\r\n<h2 id=\"tab2\" >Hydrogen bomb was first demonstration</h2>\r\nThe first demonstration of nuclear fusion — the hydrogen bomb — was conducted by the military. A hydrogen bomb is approximately 1,000 times as powerful as an ordinary atomic bomb.\r\n\r\nThe isotopes of hydrogen needed for the hydrogen bomb fusion reaction were placed around an ordinary fission bomb. The explosion of the fission bomb released the energy needed to provide the <i>activation energy</i> (the energy necessary to initiate, or start, the reaction) for the fusion process.\r\n<h2 id=\"tab3\" >Control issues with nuclear fusion</h2>\r\nThe goal of scientists for the last 50 years has been the controlled release of energy from a fusion reaction. If the energy from a fusion reaction can be released slowly, it can be used to produce electricity. It will provide an unlimited supply of energy that has no wastes to deal with or contaminants to harm the atmosphere — simply non-polluting helium.\r\n\r\nBut achieving this goal requires overcoming three problems:\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\">Temperature</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Time</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Containment</p>\r\n</li>\r\n</ul>\r\n<h3>Temperature</h3>\r\nThe fusion process requires an extremely high activation energy. Heat is used to provide the energy, but it takes a <i>lot</i> of heat to start the reaction. Scientists estimate that the sample of hydrogen isotopes must be heated to approximately 40,000,000 K.\r\n<p class=\"Remember\">K represents the Kelvin temperature scale. To get the Kelvin temperature, you add 273 to the Celsius temperature.</p>\r\nNow 40,000,000 K is hotter than the sun! At this temperature, the electrons have long since left the building; all that’s left is a positively charged <i>plasma</i>, bare nuclei heated to a tremendously high temperature. Presently, scientists are trying to heat samples to this high temperature through two ways — magnetic fields and lasers. Neither one has yet achieved the necessary temperature.\r\n<h3>Time</h3>\r\nTime is the second problem scientists must overcome to achieve the controlled release of energy from fusion reactions. The charged nuclei must be held together close enough and long enough for the fusion reaction to start. Scientists estimate that the plasma needs to be held together at 40,000,000 K for about one second.\r\n<h3>Containment</h3>\r\nContainment is the major problem facing fusion research. At 40,000,000 K, everything is a gas. The best ceramics developed for the space program would vaporize when exposed to this temperature.\r\n\r\nBecause the plasma has a charge, magnetic fields can be used to contain it — like a magnetic bottle. But if the bottle leaks, the reaction won’t take place. And scientists have yet to create a magnetic field that won’t allow the plasma to leak.\r\n\r\nUsing lasers to zap the hydrogen isotope mixture and provide the necessary energy bypasses the containment problem. But scientists have not figured out how to protect the lasers themselves from the fusion reaction.\r\n<h2 id=\"tab4\" >Another Possible Use of Fusion</h2>\r\nAn interesting by-product of fusion research is the <i>fusion torch</i> concept. With this idea, the fusion plasma, which must be cooled in order to produce steam, is used to incinerate garbage and solid wastes. Then the individual atoms and small molecules that are produced are collected and used as raw materials for industry. It seems like an ideal way to close the loop between waste and raw materials. Time will tell if this concept will eventually make it into practice.","description":"Nuclear fusion is essentially the opposite of nuclear fission. In fission, a heavy nucleus is split into smaller nuclei. With fusion, lighter nuclei are fused into a heavier nucleus.\r\n\r\n[caption id=\"attachment_296438\" align=\"alignnone\" width=\"630\"]<img class=\"size-full wp-image-296438\" src=\"https://www.dummies.com/wp-content/uploads/fusion-diagram-adobestock_392113805.jpg\" alt=\"Diagram of nuclear fusion reaction\" width=\"630\" height=\"378\" /> ©Uday / Adobe Stock[/caption]\r\n\r\nThe fusion process is the reaction that powers the sun. On the sun, in a series of nuclear reactions, four isotopes of hydrogen-1 are fused into a helium-4 with the release of a tremendous amount of energy.\r\n\r\nHere on earth, two other isotopes of hydrogen are used: H-2, called deuterium, and H-3, called tritium. Deuterium is a minor isotope of hydrogen, but it’s still relatively abundant. Tritium doesn’t occur naturally, but it can easily be produced by bombarding deuterium with a neutron.\r\n\r\nThe fusion reaction is shown in the following equation:\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/167931.image0.png\" alt=\"image0.png\" width=\"133\" height=\"25\" />\r\n<h2 id=\"tab1\" >Major breakthrough in 2022</h2>\r\nIn December 2022, scientists at the U.S. National Ignition Facility in Livermore, California, achieved a major breakthrough in nuclear fusion research: <em>energy gain</em>. Energy gain, also known in this context as <em>ignition</em>, means that they were able to create a fusion reaction that released more energy than they put in by their lab's gigantic high-powered lasers.\r\n\r\nThe scientists said they proved nuclear fusion can work on Earth, but we are still many years from being able to use it in power plants. Yet, scientists are optimistic that controlled fusion power will be achieved. The rewards are great — an unlimited source of clean energy.\r\n<h2 id=\"tab2\" >Hydrogen bomb was first demonstration</h2>\r\nThe first demonstration of nuclear fusion — the hydrogen bomb — was conducted by the military. A hydrogen bomb is approximately 1,000 times as powerful as an ordinary atomic bomb.\r\n\r\nThe isotopes of hydrogen needed for the hydrogen bomb fusion reaction were placed around an ordinary fission bomb. The explosion of the fission bomb released the energy needed to provide the <i>activation energy</i> (the energy necessary to initiate, or start, the reaction) for the fusion process.\r\n<h2 id=\"tab3\" >Control issues with nuclear fusion</h2>\r\nThe goal of scientists for the last 50 years has been the controlled release of energy from a fusion reaction. If the energy from a fusion reaction can be released slowly, it can be used to produce electricity. It will provide an unlimited supply of energy that has no wastes to deal with or contaminants to harm the atmosphere — simply non-polluting helium.\r\n\r\nBut achieving this goal requires overcoming three problems:\r\n<ul class=\"level-one\">\r\n \t<li>\r\n<p class=\"first-para\">Temperature</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Time</p>\r\n</li>\r\n \t<li>\r\n<p class=\"first-para\">Containment</p>\r\n</li>\r\n</ul>\r\n<h3>Temperature</h3>\r\nThe fusion process requires an extremely high activation energy. Heat is used to provide the energy, but it takes a <i>lot</i> of heat to start the reaction. Scientists estimate that the sample of hydrogen isotopes must be heated to approximately 40,000,000 K.\r\n<p class=\"Remember\">K represents the Kelvin temperature scale. To get the Kelvin temperature, you add 273 to the Celsius temperature.</p>\r\nNow 40,000,000 K is hotter than the sun! At this temperature, the electrons have long since left the building; all that’s left is a positively charged <i>plasma</i>, bare nuclei heated to a tremendously high temperature. Presently, scientists are trying to heat samples to this high temperature through two ways — magnetic fields and lasers. Neither one has yet achieved the necessary temperature.\r\n<h3>Time</h3>\r\nTime is the second problem scientists must overcome to achieve the controlled release of energy from fusion reactions. The charged nuclei must be held together close enough and long enough for the fusion reaction to start. Scientists estimate that the plasma needs to be held together at 40,000,000 K for about one second.\r\n<h3>Containment</h3>\r\nContainment is the major problem facing fusion research. At 40,000,000 K, everything is a gas. The best ceramics developed for the space program would vaporize when exposed to this temperature.\r\n\r\nBecause the plasma has a charge, magnetic fields can be used to contain it — like a magnetic bottle. But if the bottle leaks, the reaction won’t take place. And scientists have yet to create a magnetic field that won’t allow the plasma to leak.\r\n\r\nUsing lasers to zap the hydrogen isotope mixture and provide the necessary energy bypasses the containment problem. But scientists have not figured out how to protect the lasers themselves from the fusion reaction.\r\n<h2 id=\"tab4\" >Another Possible Use of Fusion</h2>\r\nAn interesting by-product of fusion research is the <i>fusion torch</i> concept. With this idea, the fusion plasma, which must be cooled in order to produce steam, is used to incinerate garbage and solid wastes. Then the individual atoms and small molecules that are produced are collected and used as raw materials for industry. It seems like an ideal way to close the loop between waste and raw materials. Time will tell if this concept will eventually make it into practice.","blurb":"","authors":[],"primaryCategoryTaxonomy":{"categoryId":33763,"title":"Environmental Science","slug":"environmental-science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33763"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[{"label":"Major breakthrough in 2022","target":"#tab1"},{"label":"Hydrogen bomb was first demonstration","target":"#tab2"},{"label":"Control issues with nuclear fusion","target":"#tab3"},{"label":"Another Possible Use of Fusion","target":"#tab4"}],"relatedArticles":{"fromBook":[{"articleId":208460,"title":"Physics I For Dummies Cheat Sheet","slug":"physics-i-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208460"}},{"articleId":184049,"title":"A List of Physics Constants","slug":"a-list-of-physics-constants","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/184049"}},{"articleId":184043,"title":"Physics Equations and Formulas","slug":"physics-equations-and-formulas","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/184043"}},{"articleId":174308,"title":"Calculating Tangential Velocity on a Curve","slug":"calculating-tangential-velocity-on-a-curve","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/174308"}},{"articleId":174307,"title":"Flowing from Hot to Cold: The Second Law of Thermodynamics","slug":"flowing-from-hot-to-cold-the-second-law-of-thermodynamics","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/174307"}}],"fromCategory":[{"articleId":292097,"title":"Find New Ways to Go Green this Earth Day","slug":"this-earth-day-find-new-ways-to-go-green","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/292097"}},{"articleId":291362,"title":"Climate Change For Dummies Cheat Sheet","slug":"climate-change-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/291362"}},{"articleId":284309,"title":"Check Out the Bones on Those Osteichthyes!","slug":"check-out-the-bones-on-those-osteichthyes","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/284309"}},{"articleId":284296,"title":"Elasmobranchii: Sharks, Skates, and Rays","slug":"elasmobranchii-sharks-skates-and-rays","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/284296"}},{"articleId":284288,"title":"Cephalopods: Head and Tentacles Above the Rest","slug":"cephalopods-head-and-tentacles-above-the-rest","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/284288"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":282467,"slug":"physics-i-for-dummies","isbn":"9781119872221","categoryList":["academics-the-arts","science","physics"],"amazon":{"default":"https://www.amazon.com/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/1119872227-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":"https://www.dummies.com/wp-content/uploads/9781119872221-203x255.jpg","width":203,"height":255},"title":"Physics I For Dummies","testBankPinActivationLink":"","bookOutOfPrint":true,"authorsInfo":"<p><b> Dr. <b data-author-id=\"8967\">Steven Holzner</b></b> has written more than 40 books about physics and programming. He was a contributing editor at <i>PC Magazine</i> and was on the faculty at both MIT and Cornell. He has authored Dummies titles including <i>Physics For Dummies</i> and <i>Physics Essentials For Dummies.</i> Dr. Holzner received his PhD at Cornell.</p>","authors":[{"authorId":8967,"name":"Steven Holzner","slug":"steven-holzner","description":" <p><b> Dr. Steven Holzner</b> has written more than 40 books about physics and programming. He was a contributing editor at <i>PC Magazine</i> and was on the faculty at both MIT and Cornell. He has authored Dummies titles including <i>Physics For Dummies</i> and <i>Physics Essentials For Dummies.</i> Dr. Holzner received his PhD at Cornell.</p> ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/8967"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;environmental-science&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119872221&quot;]}]\" id=\"du-slot-63b7105f10012\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;environmental-science&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119872221&quot;]}]\" id=\"du-slot-63b7105f1057b\"></div></div>"},"articleType":{"articleType":"Articles","articleList":null,"content":null,"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Explore","lifeExpectancy":"Five years","lifeExpectancySetFrom":"2022-12-21T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":194225},{"headers":{"creationTime":"2016-03-27T16:56:20+00:00","modifiedTime":"2022-12-23T15:49:44+00:00","timestamp":"2022-12-23T18:01:02+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Biology","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33760"},"slug":"biology","categoryId":33760}],"title":"Biology For Dummies Cheat Sheet","strippedTitle":"biology for dummies cheat sheet","slug":"biology-for-dummies-cheat-sheet","canonicalUrl":"","seo":{"metaDescription":"Discover human biology, biological evolution, and biological reproduction and cell division in easy-to-understand terms.","noIndex":0,"noFollow":0},"content":"Biology is the study of the living world. All living things share certain common properties:\r\n<ul>\r\n \t<li>They are made of cells that contain DNA.</li>\r\n \t<li>They maintain order inside their cells and bodies.</li>\r\n \t<li>They regulate their systems.</li>\r\n \t<li>They respond to signals in the environment.</li>\r\n \t<li>They transfer energy between themselves and their environment.</li>\r\n \t<li>They grow and develop; they reproduce.</li>\r\n \t<li>They have traits that have evolved over time.</li>\r\n</ul>","description":"Biology is the study of the living world. All living things share certain common properties:\r\n<ul>\r\n \t<li>They are made of cells that contain DNA.</li>\r\n \t<li>They maintain order inside their cells and bodies.</li>\r\n \t<li>They regulate their systems.</li>\r\n \t<li>They respond to signals in the environment.</li>\r\n \t<li>They transfer energy between themselves and their environment.</li>\r\n \t<li>They grow and develop; they reproduce.</li>\r\n \t<li>They have traits that have evolved over time.</li>\r\n</ul>","blurb":"","authors":[{"authorId":9201,"name":"Rene Fester Kratz","slug":"rene-fester-kratz","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9201"}}],"primaryCategoryTaxonomy":{"categoryId":33760,"title":"Biology","slug":"biology","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33760"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[],"relatedArticles":{"fromBook":[{"articleId":241857,"title":"10 Ways Biology Affects Your Life","slug":"10-ways-biology-affects-life","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/241857"}},{"articleId":241854,"title":"10 Great Biology Discoveries","slug":"10-great-biology-discoveries","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/241854"}},{"articleId":241851,"title":"Plant Growth and Development: Sending Signals with Plant Hormones","slug":"plant-growth-development-sending-signals-plant-hormones","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/241851"}},{"articleId":241846,"title":"How Living Things Obtain Matter and Energy for Growth","slug":"living-things-obtain-matter-energy-growth","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/241846"}},{"articleId":241843,"title":"Gender Differentiation in Humans","slug":"gender-differentiation-humans","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/241843"}}],"fromCategory":[{"articleId":270004,"title":"Your Body, Your Cells: Eukaryotic Cells","slug":"your-body-your-cells-eukaryotic-cells","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/270004"}},{"articleId":269999,"title":"How to Use Recombinant DNA Technology to Solve Problems","slug":"how-to-use-recombinant-dna-technology-to-solve-problems","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/269999"}},{"articleId":269996,"title":"Recombinant DNA Technology","slug":"recombinant-dna-technology","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/269996"}},{"articleId":269993,"title":"Gene Expression in Bacteria","slug":"gene-expression-in-bacteria","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/269993"}},{"articleId":269962,"title":"Metabolic Pathways","slug":"metabolic-pathways","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/269962"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":281996,"slug":"biology-for-dummies-3rd-edition","isbn":"9781119345374","categoryList":["academics-the-arts","science","biology"],"amazon":{"default":"https://www.amazon.com/gp/product/1119345375/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/1119345375/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/1119345375-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/1119345375/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/1119345375/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":"https://www.dummies.com/wp-content/uploads/biology-for-dummies-3rd-edition-cover-9781119345374-203x255.jpg","width":203,"height":255},"title":"Biology For Dummies","testBankPinActivationLink":"","bookOutOfPrint":false,"authorsInfo":"<p><b data-author-id=\"9201\">René Fester Kratz, PhD,</b> teaches biology at Everett Community College. Dr. Kratz holds a PhD in Botany from the University of Washington. She works with other scientists and K?12 teachers to develop science curricula that align with national learning standards and the latest research on human learning. </p>","authors":[{"authorId":9201,"name":"Rene Fester Kratz","slug":"rene-fester-kratz","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9201"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[{"title":"For the Spring Term Student","slug":"for-the-spring-term-student","collectionId":296450}],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;biology&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119345374&quot;]}]\" id=\"du-slot-63a5ecdea550b\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;biology&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119345374&quot;]}]\" id=\"du-slot-63a5ecdea5a5b\"></div></div>"},"articleType":{"articleType":"Cheat Sheet","articleList":[{"articleId":192645,"title":"Key Concepts in Human Biology and Physiology","slug":"key-concepts-in-human-biology-and-physiology","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192645"}},{"articleId":192644,"title":"Natural Selection and Biological Evolution","slug":"natural-selection-and-biological-evolution","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192644"}},{"articleId":192641,"title":"Biological Reproduction and Cell Division","slug":"biological-reproduction-and-cell-division","categoryList":["academics-the-arts","science","biology"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/192641"}}],"content":[{"title":"Key concepts in human biology and physiology ","thumb":null,"image":null,"content":"<div class=\"custom-spynav\" data-v-98c17f9c=\"\" data-v-76ccd6ad=\"\">\n<div class=\"custom-spynav-desktop\" data-v-98c17f9c=\"\">\n<div class=\"sticky-sidebar\" data-v-98c17f9c=\"\">\n<p>The study of biology includes the study of human beings. The biological functions of humans are similar to those of many other animals. Like other animals, humans need to acquire oxygen and energy in order to survive. Here is a brief summary of key human biological concepts:</p>\n</div>\n</div>\n</div>\n<div class=\"middle-content\" data-v-76ccd6ad=\"\">\n<div id=\"inner-middle-content\" class=\"inner-middle-content\" data-v-76ccd6ad=\"\">\n<div id=\"article-content-wrapper\" data-v-89b5964a=\"\" data-v-76ccd6ad=\"\">\n<article class=\"article-content\" data-v-89b5964a=\"\" data-testid=\"articleContent\">\n<ul class=\"level-one\">\n<li>\n<p class=\"first-para\">Organisms are made of organ systems, which are made of organs, which are made of tissues, which are made of cells, which are made of molecules, which are made of atoms.</p>\n</li>\n<li>\n<p class=\"first-para\">Homeostasis is the balance, or equilibrium, of the body. Regulation of all the body’s systems seeks to keep the body in homeostasis.</p>\n</li>\n<li>\n<p class=\"first-para\">The heart is a muscular pump. Contractions by the heart push blood through the circulatory system.</p>\n</li>\n<li>\n<p class=\"first-para\">Within the circulatory system, blood travels in arteries to carry oxygen from the lungs to the tissues and returns through veins to carry carbon dioxide from the tissues to the lungs. Blood also carries nutrients from the digestive system to the cells of the body and removes wastes from the cells.</p>\n</li>\n<li>\n<p class=\"first-para\">Exchange of the respiratory gases, oxygen and carbon dioxide, occurs in the lungs.</p>\n</li>\n<li>\n<p class=\"first-para\">Digestion involves the mechanical and chemical breakdown of food molecules into their smallest subunits. Digestion begins in the mouth and continues in the stomach and small intestine.</p>\n</li>\n<li>\n<p class=\"first-para\">Absorption of nutrients in the digestive system occurs through the cells of the small intestine.</p>\n</li>\n<li>\n<p class=\"first-para\">Glands are organs in the endocrine system that secrete hormones. Hormones are chemical messengers that can alter the behavior of target cells.</p>\n</li>\n<li>\n<p class=\"first-para\">The nervous system consists of two main systems, the central nervous system (CNS) and the peripheral nervous system. The CNS is made up of the brain and spinal cord and sends out instructions. The peripheral nervous system contains the nerves that send the messages from the CNS to the rest of the body.</p>\n</li>\n<li>\n<p class=\"first-para\">The muscular and skeletal systems work together to allow movement. The muscles contain fibers that can contract, while the skeleton provides support and structures for muscles to pull against.</p>\n</li>\n</ul>\n</article>\n</div>\n</div>\n</div>\n"},{"title":"Natural selection and biological evolution ","thumb":null,"image":null,"content":"<p>When studying Biology, you&#8217;ll hear about biological evolution, which refers to the change of living things over time. Charles Darwin concluded that biological evolution occurs as a result of natural selection, which is the theory that in any given generation, some individuals are more likely to survive and reproduce than others. In order for natural selection to occur in a population, several conditions must be met:</p>\n<ul class=\"level-one\">\n<li>\n<p class=\"first-para\"><b>Individuals in the population must produce more offspring than can survive.</b> Human beings are somewhat unique among living things in that we can make conscious choices about how many offspring we have. Most other organisms, however, produce as many offspring as they can.</p>\n</li>\n<li>\n<p class=\"first-para\"><b>Those individuals must have different characteristics.</b> During Darwin’s time, no one knew where these differences came from. Now scientists know that differences in organisms arise due to mutations in DNA combined with the mixing of genetic information during sexual reproduction.</p>\n</li>\n<li>\n<p class=\"first-para\"><b>Offspring must inherit some characteristics from their parents. </b>During Darwin’s time, the laws of inheritance were just beginning to be figured out, so Darwin didn’t know exactly how parents passed on their traits. Modern scientists know that traits are inherited when parents pass genes on to their offspring.</p>\n</li>\n<li>\n<p class=\"first-para\"><b>Organisms with the best-suited characteristics for their environment are more likely to survive and reproduce.</b> This is the heart of natural selection. If there’s competition for survival and not all the organisms are the same, then the ones with the advantageous traits are more likely to survive. If these traits can be inherited, then the next generation will show more of these advantageous traits.</p>\n</li>\n</ul>\n<p>If these four conditions are met, then the new generation of individuals will be different from the original generation in the frequency and distribution of traits, which is pretty much the definition of biological evolution.</p>\n"},{"title":"Biological reproduction and cell division ","thumb":null,"image":null,"content":"<p>Biology is all about life. In order for life to continue, <a href=\"https://www.dummies.com/education/science/biology/human-biology-fertilization-through-birth/\" target=\"_blank\" rel=\"noopener\">reproduction</a> has to occur at the cellular level so that genetic information (DNA) is replicated. The following concepts (mitosis and meiosis) are key to understanding how cells reproduce:</p>\n<ul class=\"level-one\">\n<li>\n<p class=\"first-para\">Cells do <b>mitosis</b> when they are going to make an exact copy of themselves for asexual reproduction, growth, or tissue repair. <a href=\"https://www.dummies.com/education/science/biology/dna-replication/\" target=\"_blank\" rel=\"noopener\">DNA replication</a> occurs once, followed by a single division. The parent and daughter cells are both diploid, which means they have a double set of chromosomes.</p>\n</li>\n<li>\n<p class=\"first-para\">Cells do <b>meiosis</b> in order to produce gametes (eggs and sperm) for sexual reproduction. DNA replication occurs once, followed by two divisions. The parent cell is diploid, but the daughter cells are haploid, which means they have half the number of chromosomes as their parent cells.</p>\n</li>\n</ul>\n"}],"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Advance","lifeExpectancy":"Two years","lifeExpectancySetFrom":"2022-02-25T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":209035},{"headers":{"creationTime":"2016-03-26T17:23:25+00:00","modifiedTime":"2022-12-23T15:45:58+00:00","timestamp":"2022-12-23T18:01:02+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Physics","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33769"},"slug":"physics","categoryId":33769}],"title":"How to Calculate a Spring Constant Using Hooke's Law","strippedTitle":"how to calculate a spring constant using hooke's law","slug":"how-to-calculate-a-spring-constant-using-hookes-law","canonicalUrl":"","seo":{"metaDescription":"Learn about Hooke's law and how to calculate the spring constant, including the formula and insight on a spring's impact on force.","noIndex":0,"noFollow":0},"content":"Any physicist knows that if an object applies a force to a spring, then the spring applies an equal and opposite force to the object. <a href=\"https://www.dummies.com/education/science/using-a-generalized-hookes-law-for-stress-and-strain/\" target=\"_blank\" rel=\"noopener\">Hooke’s law</a> gives the force a spring exerts on an object attached to it with the following equation:\r\n\r\n<i>F</i> = –<i>kx</i>\r\n\r\nThe minus sign shows that this force is in the opposite direction of the force that’s stretching or compressing the spring. The variables of the equation are <em>F,</em> which represents force, <em>k, </em>which is called the spring constant and measures how stiff and strong the spring is, and <em>x,</em> the distance the spring is stretched or compressed away from its equilibrium or rest position.\r\n\r\nThe force exerted by a spring is called a <i>restoring force;</i> it always acts to restore the spring toward equilibrium.\r\n\r\nIn Hooke’s law, the negative sign on the spring’s force means that the force exerted by the spring opposes the spring’s displacement.\r\n<h2 id=\"tab1\" >Understanding springs and their direction of force</h2>\r\n<img class=\"aligncenter wp-image-239155 size-full\" src=\"https://www.dummies.com/wp-content/uploads/direction-of-force-in-springs.jpg\" alt=\"direction of force exzerted in springs\" width=\"535\" height=\"285\" />\r\n<div class=\"imageBlock\" style=\"width: 535px;\">\r\n<div class=\"imageCaption\">The direction of force exerted by a spring</div>\r\n</div>\r\nThe preceding figure shows a ball attached to a spring. You can see that if the spring isn’t stretched or compressed, it exerts no force on the ball. If you push the spring, however, it pushes back, and if you pull the spring, it pulls back.\r\n<p class=\"Remember\">Hooke’s law is valid as long as the elastic material you’re dealing with stays elastic — that is, it stays within its <i><a href=\"https://www.dummies.com/education/science/physics/how-to-calculate-the-potential-and-kinetic-energy-in-a-spring/\" target=\"_blank\" rel=\"noopener\">elastic limit</a>.</i> If you pull a spring too far, it loses its stretchy ability. As long as a spring stays within its elastic limit, you can say that <i>F</i> = –<i>kx</i>.</p>\r\n<p class=\"Remember\">When a spring stays within its elastic limit and obeys Hooke’s law, the spring is called an <i>ideal spring.</i></p>\r\n\r\n<h2 id=\"tab2\" >How to find the spring constant (example problem)</h2>\r\nSuppose that a group of car designers knocks on your door and asks whether you can help design a suspension system. “Sure,” you say. They inform you that the car will have a mass of 1,000 kilograms, and you have four shock absorbers, each 0.5 meters long, to work with. How strong do the springs have to be? Assuming these shock absorbers use springs, each one has to support a mass of at least 250 kilograms, which weighs the following:\r\n\r\n<i>F</i> = <i>mg</i> = (250 kg)(9.8 m/s<sup>2</sup>) = 2,450 N\r\n\r\nwhere <i>F</i> equals force, <i>m</i> equals the mass of the object, and <i>g</i> equals the acceleration due to gravity, 9.8 meters per second<sup>2</sup>. The spring in the shock absorber will, at a minimum, have to give you 2,450 newtons of force at the maximum compression of 0.5 meters. What does this mean the spring constant should be?\r\n\r\nIn order to figure out <strong>how to calculate the spring constant</strong>, we must remember what Hooke’s law says:\r\n\r\n<i>F</i> = –<i>kx</i>\r\n\r\nNow, we need to rework the equation so that we are calculating for the missing metric, which is the spring constant, or <em>k</em>. Looking only at the magnitudes and therefore omitting the negative sign, you get\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/330102.image1.png\" alt=\"image1.png\" width=\"41\" height=\"37\" />\r\n\r\nTime to plug in the numbers:\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/330103.image2.png\" alt=\"image2.png\" width=\"195\" height=\"39\" />\r\n\r\nThe springs used in the shock absorbers must have spring constants of at least 4,900 newtons per meter. The car designers rush out, ecstatic, but you call after them, “Don’t forget, you need to at least double that if you actually want your car to be able to handle potholes.”","description":"Any physicist knows that if an object applies a force to a spring, then the spring applies an equal and opposite force to the object. <a href=\"https://www.dummies.com/education/science/using-a-generalized-hookes-law-for-stress-and-strain/\" target=\"_blank\" rel=\"noopener\">Hooke’s law</a> gives the force a spring exerts on an object attached to it with the following equation:\r\n\r\n<i>F</i> = –<i>kx</i>\r\n\r\nThe minus sign shows that this force is in the opposite direction of the force that’s stretching or compressing the spring. The variables of the equation are <em>F,</em> which represents force, <em>k, </em>which is called the spring constant and measures how stiff and strong the spring is, and <em>x,</em> the distance the spring is stretched or compressed away from its equilibrium or rest position.\r\n\r\nThe force exerted by a spring is called a <i>restoring force;</i> it always acts to restore the spring toward equilibrium.\r\n\r\nIn Hooke’s law, the negative sign on the spring’s force means that the force exerted by the spring opposes the spring’s displacement.\r\n<h2 id=\"tab1\" >Understanding springs and their direction of force</h2>\r\n<img class=\"aligncenter wp-image-239155 size-full\" src=\"https://www.dummies.com/wp-content/uploads/direction-of-force-in-springs.jpg\" alt=\"direction of force exzerted in springs\" width=\"535\" height=\"285\" />\r\n<div class=\"imageBlock\" style=\"width: 535px;\">\r\n<div class=\"imageCaption\">The direction of force exerted by a spring</div>\r\n</div>\r\nThe preceding figure shows a ball attached to a spring. You can see that if the spring isn’t stretched or compressed, it exerts no force on the ball. If you push the spring, however, it pushes back, and if you pull the spring, it pulls back.\r\n<p class=\"Remember\">Hooke’s law is valid as long as the elastic material you’re dealing with stays elastic — that is, it stays within its <i><a href=\"https://www.dummies.com/education/science/physics/how-to-calculate-the-potential-and-kinetic-energy-in-a-spring/\" target=\"_blank\" rel=\"noopener\">elastic limit</a>.</i> If you pull a spring too far, it loses its stretchy ability. As long as a spring stays within its elastic limit, you can say that <i>F</i> = –<i>kx</i>.</p>\r\n<p class=\"Remember\">When a spring stays within its elastic limit and obeys Hooke’s law, the spring is called an <i>ideal spring.</i></p>\r\n\r\n<h2 id=\"tab2\" >How to find the spring constant (example problem)</h2>\r\nSuppose that a group of car designers knocks on your door and asks whether you can help design a suspension system. “Sure,” you say. They inform you that the car will have a mass of 1,000 kilograms, and you have four shock absorbers, each 0.5 meters long, to work with. How strong do the springs have to be? Assuming these shock absorbers use springs, each one has to support a mass of at least 250 kilograms, which weighs the following:\r\n\r\n<i>F</i> = <i>mg</i> = (250 kg)(9.8 m/s<sup>2</sup>) = 2,450 N\r\n\r\nwhere <i>F</i> equals force, <i>m</i> equals the mass of the object, and <i>g</i> equals the acceleration due to gravity, 9.8 meters per second<sup>2</sup>. The spring in the shock absorber will, at a minimum, have to give you 2,450 newtons of force at the maximum compression of 0.5 meters. What does this mean the spring constant should be?\r\n\r\nIn order to figure out <strong>how to calculate the spring constant</strong>, we must remember what Hooke’s law says:\r\n\r\n<i>F</i> = –<i>kx</i>\r\n\r\nNow, we need to rework the equation so that we are calculating for the missing metric, which is the spring constant, or <em>k</em>. Looking only at the magnitudes and therefore omitting the negative sign, you get\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/330102.image1.png\" alt=\"image1.png\" width=\"41\" height=\"37\" />\r\n\r\nTime to plug in the numbers:\r\n\r\n<img src=\"https://www.dummies.com/wp-content/uploads/330103.image2.png\" alt=\"image2.png\" width=\"195\" height=\"39\" />\r\n\r\nThe springs used in the shock absorbers must have spring constants of at least 4,900 newtons per meter. The car designers rush out, ecstatic, but you call after them, “Don’t forget, you need to at least double that if you actually want your car to be able to handle potholes.”","blurb":"","authors":[{"authorId":8967,"name":"Steven Holzner","slug":"steven-holzner","description":" <p><b> Dr. Steven Holzner</b> has written more than 40 books about physics and programming. He was a contributing editor at <i>PC Magazine</i> and was on the faculty at both MIT and Cornell. He has authored Dummies titles including <i>Physics For Dummies</i> and <i>Physics Essentials For Dummies.</i> Dr. Holzner received his PhD at Cornell.</p> ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/8967"}}],"primaryCategoryTaxonomy":{"categoryId":33769,"title":"Physics","slug":"physics","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33769"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[{"label":"Understanding springs and their direction of force","target":"#tab1"},{"label":"How to find the spring constant (example problem)","target":"#tab2"}],"relatedArticles":{"fromBook":[{"articleId":208460,"title":"Physics I For Dummies Cheat Sheet","slug":"physics-i-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208460"}},{"articleId":194225,"title":"How Does Nuclear Fusion Work?","slug":"nuclear-fusion-the-hope-for-our-energy-future","categoryList":["academics-the-arts","science","environmental-science"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/194225"}},{"articleId":184049,"title":"A List of Physics Constants","slug":"a-list-of-physics-constants","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/184049"}},{"articleId":184043,"title":"Physics Equations and Formulas","slug":"physics-equations-and-formulas","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/184043"}},{"articleId":174308,"title":"Calculating Tangential Velocity on a Curve","slug":"calculating-tangential-velocity-on-a-curve","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/174308"}}],"fromCategory":[{"articleId":209405,"title":"String Theory For Dummies Cheat Sheet","slug":"string-theory-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/209405"}},{"articleId":209012,"title":"Physics II For Dummies Cheat Sheet","slug":"physics-ii-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/209012"}},{"articleId":208592,"title":"Thermodynamics For Dummies Cheat Sheet","slug":"thermodynamics-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208592"}},{"articleId":208578,"title":"Optics For Dummies Cheat Sheet","slug":"optics-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208578"}},{"articleId":208460,"title":"Physics I For Dummies Cheat Sheet","slug":"physics-i-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/208460"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":282467,"slug":"physics-i-for-dummies","isbn":"9781119872221","categoryList":["academics-the-arts","science","physics"],"amazon":{"default":"https://www.amazon.com/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/1119872227-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/1119872227/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":"https://www.dummies.com/wp-content/uploads/9781119872221-203x255.jpg","width":203,"height":255},"title":"Physics I For Dummies","testBankPinActivationLink":"","bookOutOfPrint":true,"authorsInfo":"<p><b> Dr. <b data-author-id=\"8967\">Steven Holzner</b></b> has written more than 40 books about physics and programming. He was a contributing editor at <i>PC Magazine</i> and was on the faculty at both MIT and Cornell. He has authored Dummies titles including <i>Physics For Dummies</i> and <i>Physics Essentials For Dummies.</i> Dr. Holzner received his PhD at Cornell.</p>","authors":[{"authorId":8967,"name":"Steven Holzner","slug":"steven-holzner","description":" <p><b> Dr. Steven Holzner</b> has written more than 40 books about physics and programming. He was a contributing editor at <i>PC Magazine</i> and was on the faculty at both MIT and Cornell. He has authored Dummies titles including <i>Physics For Dummies</i> and <i>Physics Essentials For Dummies.</i> Dr. Holzner received his PhD at Cornell.</p> ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/8967"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[{"title":"For the Spring Term Student","slug":"for-the-spring-term-student","collectionId":296450}],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;physics&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119872221&quot;]}]\" id=\"du-slot-63a5ecde9d57a\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;physics&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119872221&quot;]}]\" id=\"du-slot-63a5ecde9daa9\"></div></div>"},"articleType":{"articleType":"Articles","articleList":null,"content":null,"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Advance","lifeExpectancy":"Five years","lifeExpectancySetFrom":"2021-09-10T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":174221},{"headers":{"creationTime":"2016-03-26T18:02:35+00:00","modifiedTime":"2022-12-14T14:49:07+00:00","timestamp":"2022-12-14T15:01:03+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Physics","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33769"},"slug":"physics","categoryId":33769}],"title":"More Dimensions Make String Theory Work","strippedTitle":"more dimensions make string theory work","slug":"more-dimensions-make-string-theory-work","canonicalUrl":"","seo":{"metaDescription":"For most interpretations, superstring theory requires a large number of extra space dimensions to be mathematically consistent: M-theory requires ten space dime","noIndex":0,"noFollow":0},"content":"For most interpretations, superstring theory requires a large number of extra space dimensions to be mathematically consistent: M-theory requires ten space dimensions. With the introduction of branes as multidimensional objects in string theory, it becomes possible to construct and imagine wildly creative geometries for space that correspond to different possible particles and forces. It’s unclear, at present, whether those extra dimensions exist or are just mathematical artifacts.\r\n<p class=\"Remember\">The reason string theory requires extra dimensions is that trying to eliminate them results in much more complicated mathematical equations. It’s not impossible, but most physicists haven’t pursued these concepts in a great deal of depth, leaving science (perhaps by default) with a theory that requires many extra dimensions.</p>\r\nFrom the time of Descartes, mathematicians have been able to translate between geometric and physical representations. Mathematicians can tackle their equations in virtually any number of dimensions that they choose, even if they can’t visually picture what they’re talking about.\r\n<p class=\"Tip\">One of the tools mathematicians use in exploring higher dimensions is analogy. If you start with a zero-dimensional point and extend it through space, you get a one-dimensional line. If you take that line and extend it into a second dimension, you end up with a square.</p>\r\nIf you extend a square through a third dimension, you end up with a cube. If you then were to take a cube and extend into a fourth dimension, you’d get a shape called a <i>hypercube.</i>\r\n\r\nA line has two “corners” but extending it to a square gives four corners, while a cube has eight corners. By continuing to extend this algebraic relationship, a hypercube would be a four-dimensional object with 16 corners, and a similar relationship can be used to create analogous objects in additional dimensions. Such objects are obviously well outside of what our minds can picture.\r\n<p class=\"Tip\">Humans aren’t psychologically wired to be able to picture more than three space dimensions. A handful of mathematicians (and possibly some physicists) have devoted their lives to the study of extra dimensions so fully that they may be able to actually picture a four-dimensional object, such as a hypercube. Most mathematicians can’t (so don’t feel bad if you can’t).</p>\r\nWhole fields of mathematics — linear algebra, abstract algebra, topology, knot theory, complex analysis, and others — exist with the sole purpose of trying to take abstract concepts, frequently with large numbers of possible variables, degrees of freedom, or dimensions, and make sense of them.\r\n\r\nThese sorts of mathematical tools are at the heart of string theory. Regardless of the ultimate success or failure of string theory as a physical model of reality, it has motivated mathematics to grow and explore new questions in new ways, and for that alone, it has proved useful.","description":"For most interpretations, superstring theory requires a large number of extra space dimensions to be mathematically consistent: M-theory requires ten space dimensions. With the introduction of branes as multidimensional objects in string theory, it becomes possible to construct and imagine wildly creative geometries for space that correspond to different possible particles and forces. It’s unclear, at present, whether those extra dimensions exist or are just mathematical artifacts.\r\n<p class=\"Remember\">The reason string theory requires extra dimensions is that trying to eliminate them results in much more complicated mathematical equations. It’s not impossible, but most physicists haven’t pursued these concepts in a great deal of depth, leaving science (perhaps by default) with a theory that requires many extra dimensions.</p>\r\nFrom the time of Descartes, mathematicians have been able to translate between geometric and physical representations. Mathematicians can tackle their equations in virtually any number of dimensions that they choose, even if they can’t visually picture what they’re talking about.\r\n<p class=\"Tip\">One of the tools mathematicians use in exploring higher dimensions is analogy. If you start with a zero-dimensional point and extend it through space, you get a one-dimensional line. If you take that line and extend it into a second dimension, you end up with a square.</p>\r\nIf you extend a square through a third dimension, you end up with a cube. If you then were to take a cube and extend into a fourth dimension, you’d get a shape called a <i>hypercube.</i>\r\n\r\nA line has two “corners” but extending it to a square gives four corners, while a cube has eight corners. By continuing to extend this algebraic relationship, a hypercube would be a four-dimensional object with 16 corners, and a similar relationship can be used to create analogous objects in additional dimensions. Such objects are obviously well outside of what our minds can picture.\r\n<p class=\"Tip\">Humans aren’t psychologically wired to be able to picture more than three space dimensions. A handful of mathematicians (and possibly some physicists) have devoted their lives to the study of extra dimensions so fully that they may be able to actually picture a four-dimensional object, such as a hypercube. Most mathematicians can’t (so don’t feel bad if you can’t).</p>\r\nWhole fields of mathematics — linear algebra, abstract algebra, topology, knot theory, complex analysis, and others — exist with the sole purpose of trying to take abstract concepts, frequently with large numbers of possible variables, degrees of freedom, or dimensions, and make sense of them.\r\n\r\nThese sorts of mathematical tools are at the heart of string theory. Regardless of the ultimate success or failure of string theory as a physical model of reality, it has motivated mathematics to grow and explore new questions in new ways, and for that alone, it has proved useful.","blurb":"","authors":[{"authorId":9499,"name":"Andrew Zimmerman Jones","slug":"andrew-zimmerman-jones","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9499"}},{"authorId":9500,"name":"Daniel Robbins","slug":"daniel-robbins","description":"","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9500"}}],"primaryCategoryTaxonomy":{"categoryId":33769,"title":"Physics","slug":"physics","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33769"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[],"relatedArticles":{"fromBook":[{"articleId":209405,"title":"String Theory For Dummies Cheat Sheet","slug":"string-theory-for-dummies-cheat-sheet","categoryList":["academics-the-arts","science","physics"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/209405"}}],"fromCategory":[{"articleId":209405,"title":"String Theory For Dummies Cheat 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Sometimes you might not be sure where to start when you are first given a set of problems and told to go forth and succeed.","noIndex":0,"noFollow":0},"content":"Chemistry covers all kinds of stuff. Sometimes you might not be sure where to start when you are first given a set of problems and told to go forth and succeed. Sometimes it’s converting metric units, writing ionic formulas, naming covalent compounds, balancing reactions, or dealing with extensive and intensive properties.\r\n\r\nThis Cheat Sheet is designed to give you some help on a few of the trickier things you might encounter so that when you are done looking it over you can go forth and succeed!","description":"Chemistry covers all kinds of stuff. Sometimes you might not be sure where to start when you are first given a set of problems and told to go forth and succeed. Sometimes it’s converting metric units, writing ionic formulas, naming covalent compounds, balancing reactions, or dealing with extensive and intensive properties.\r\n\r\nThis Cheat Sheet is designed to give you some help on a few of the trickier things you might encounter so that when you are done looking it over you can go forth and succeed!","blurb":"","authors":[{"authorId":35209,"name":"Christopher R. Hren","slug":"christopher-r-hren","description":" <p><b>Christopher R. Hren </b>has taught high school chemistry, honors chemistry, and AP Chemistry for more than 15 years. <p><b>John T. Moore, EdD,</b> has taught chemistry at Stephen F. Austin State University in Nacogdoches, Texas, for more than 40 years. <p><b>Peter J. Mikulecky, PhD,</b> teaches science and math at Fusion Learning Center and Fusion Academy, and is a technical writer. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/35209"}}],"primaryCategoryTaxonomy":{"categoryId":33762,"title":"Chemistry","slug":"chemistry","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33762"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[],"relatedArticles":{"fromBook":[],"fromCategory":[{"articleId":253707,"title":"How to Make Unit Conversions","slug":"make-unit-conversions","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/253707"}},{"articleId":251836,"title":"How to Convert between Units Using Conversion Factors","slug":"convert-units-using-conversion-factors","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251836"}},{"articleId":251010,"title":"How to Build Derived Units from Base Units","slug":"build-derived-units-base-units","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251010"}},{"articleId":251005,"title":"How to Do Arithmetic with Significant Figures","slug":"arithmetic-significant-figures","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251005"}},{"articleId":250992,"title":"How to Add and Subtract with Exponential Notation","slug":"add-subtract-exponential-notation","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/250992"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":295574,"slug":"chemistry-all-in-one-for-dummies-chapter-quizzes-online","isbn":"9781119908319","categoryList":["academics-the-arts","science","chemistry"],"amazon":{"default":"https://www.amazon.com/gp/product/1119908310/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/1119908310/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/1119908310-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/1119908310/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/1119908310/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":null,"width":0,"height":0},"title":"Chemistry All-in-One For Dummies (+ Chapter Quizzes Online)","testBankPinActivationLink":"","bookOutOfPrint":true,"authorsInfo":"<p><p><b><b data-author-id=\"35209\">Christopher R. Hren</b> </b>has taught high school chemistry, honors chemistry, and AP Chemistry for more than 15 years. <p><b>John T. Moore, EdD,</b> has taught chemistry at Stephen F. Austin State University in Nacogdoches, Texas, for more than 40 years. <p><b>Peter J. Mikulecky, PhD,</b> teaches science and math at Fusion Learning Center and Fusion Academy, and is a technical writer. <p><b>Christopher R. Hren </b>has taught high school chemistry, honors chemistry, and AP Chemistry for more than 15 years. <p><b><b data-author-id=\"9159\">John T. Moore</b>, EdD,</b> has taught chemistry at Stephen F. Austin State University in Nacogdoches, Texas, for more than 40 years. <p><b>Peter J. Mikulecky, PhD,</b> teaches science and math at Fusion Learning Center and Fusion Academy, and is a technical writer. <p><b>Christopher R. Hren </b>has taught high school chemistry, honors chemistry, and AP Chemistry for more than 15 years. <p><b>John T. Moore, EdD,</b> has taught chemistry at Stephen F. Austin State University in Nacogdoches, Texas, for more than 40 years. <p><b><b data-author-id=\"9161\">Peter J. Mikulecky</b>, PhD,</b> teaches science and math at Fusion Learning Center and Fusion Academy, and is a technical writer.</p>","authors":[{"authorId":35209,"name":"Christopher R. Hren","slug":"christopher-r-hren","description":" <p><b>Christopher R. Hren </b>has taught high school chemistry, honors chemistry, and AP Chemistry for more than 15 years. <p><b>John T. Moore, EdD,</b> has taught chemistry at Stephen F. Austin State University in Nacogdoches, Texas, for more than 40 years. <p><b>Peter J. Mikulecky, PhD,</b> teaches science and math at Fusion Learning Center and Fusion Academy, and is a technical writer. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/35209"}},{"authorId":9159,"name":"John T. Moore","slug":"john-t-moore","description":" <p><b>Christopher R. Hren </b>has taught high school chemistry, honors chemistry, and AP Chemistry for more than 15 years. <p><b>John T. Moore, EdD,</b> has taught chemistry at Stephen F. Austin State University in Nacogdoches, Texas, for more than 40 years. <p><b>Peter J. Mikulecky, PhD,</b> teaches science and math at Fusion Learning Center and Fusion Academy, and is a technical writer. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9159"}},{"authorId":9161,"name":"Peter J. Mikulecky","slug":"peter-j-mikulecky","description":" <p><b>Christopher R. Hren </b>has taught high school chemistry, honors chemistry, and AP Chemistry for more than 15 years. <p><b>John T. Moore, EdD,</b> has taught chemistry at Stephen F. Austin State University in Nacogdoches, Texas, for more than 40 years. <p><b>Peter J. Mikulecky, PhD,</b> teaches science and math at Fusion Learning Center and Fusion Academy, and is a technical writer. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9161"}}],"_links":{"self":"https://dummies-api.dummies.com/v2/books/"}},"collections":[],"articleAds":{"footerAd":"<div class=\"du-ad-region row\" id=\"article_page_adhesion_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_adhesion_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;chemistry&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119908319&quot;]}]\" id=\"du-slot-636a6f2eb4b65\"></div></div>","rightAd":"<div class=\"du-ad-region row\" id=\"article_page_right_ad\"><div class=\"du-ad-unit col-md-12\" data-slot-id=\"article_page_right_ad\" data-refreshed=\"false\" \r\n data-target = \"[{&quot;key&quot;:&quot;cat&quot;,&quot;values&quot;:[&quot;academics-the-arts&quot;,&quot;science&quot;,&quot;chemistry&quot;]},{&quot;key&quot;:&quot;isbn&quot;,&quot;values&quot;:[&quot;9781119908319&quot;]}]\" id=\"du-slot-636a6f2eb5a50\"></div></div>"},"articleType":{"articleType":"Cheat Sheet","articleList":[{"articleId":0,"title":"","slug":null,"categoryList":[],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/"}}],"content":[{"title":"Converting metric units","thumb":null,"image":null,"content":"<p>Because chemists must be able to communicate their measurements to other chemists all over the world, they need to speak the same measurement language. This language is the SI system of measurement, related to the metric system.</p>\n<p>Below is a chart of the most commonly used metric prefixes, their abbreviations, and how they relate to a metric base unit. Remember, the metric system is based on 10s, so each time you are converting from one unit to another you can just count the number of jumps between prefixes to have an idea of what your conversion should be.</p>\n<table>\n<tbody>\n<tr>\n<td><strong>Prefix</strong></td>\n<td><strong>Abbreviation</strong></td>\n<td><strong>Meaning</strong></td>\n</tr>\n<tr>\n<td>kilo-</td>\n<td>k</td>\n<td>1,000 or 10<sup>3</sup></td>\n</tr>\n<tr>\n<td>hecto-</td>\n<td>h</td>\n<td>100 or 10<sup>2</sup></td>\n</tr>\n<tr>\n<td>deka- or deca-</td>\n<td>da</td>\n<td>10 or 10<sup>1</sup></td>\n</tr>\n<tr>\n<td>deci-</td>\n<td>d</td>\n<td>0.1 or 10<sup>–1</sup></td>\n</tr>\n<tr>\n<td>centi-</td>\n<td>c</td>\n<td>0.01 or 10<sup>–2</sup></td>\n</tr>\n<tr>\n<td>milli-</td>\n<td>m</td>\n<td>0.001 or 10<sup>–3</sup></td>\n</tr>\n</tbody>\n</table>\n<p>For example, if you want to convert 500 ml to liters, all you have to do is multiply that by the conversion shown in the chart for milli as shown below. Be sure to cancel out your units!</p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-295577\" src=\"https://www.dummies.com/wp-content/uploads/chem-formula.png\" alt=\"equation to convert 500 ml to liters\" width=\"220\" height=\"78\" /></p>\n<p><strong>Writing the formulas of ionic compounds</strong></p>\n<p>A quick way to determine the formula of an ionic compound (remember ionic compounds are metals bonded to nonmetals) is to use the <em>crisscross rule</em>. The crisscross rule uses the ionic charges of the ions to predict the formula of the ionic compound. It doesn’t work every time but it is a very useful method for writing many ionic formulas. Check it out as shown here:</p>\n<p><img loading=\"lazy\" class=\"alignnone size-full wp-image-295578\" src=\"https://www.dummies.com/wp-content/uploads/9781119908319-fgcs01.jpg\" alt=\"Diagram of crisscross rule in chemistry\" width=\"250\" height=\"108\" /></p>\n<p>Take the numerical value of the metal ion’s superscript (forget about the charge symbol) and move it to the bottom right-hand side of the nonmetal’s symbol — as a subscript. Then take the numerical value of the nonmetal’s superscript and make it the subscript of the metal. (Note that if the numerical value is 1, it’s just understood and not shown.)</p>\n<p>So, in this example, you make magnesium’s 2 a subscript of bromine and make bromine’s 1 a subscript of magnesium (but because it’s 1, you don’t show it), and you get the formula MgBr<sub>2</sub>.</p>\n"},{"title":"Naming covalent compounds","thumb":null,"image":null,"content":"<p>Covalent compounds are nonmetals to nonmetals. These differ from ionic compounds in that their names clearly specify how many of each type of atom participate in the compound. The table below shows you the prefixes used when naming covalent compounds.</p>\n<table>\n<tbody>\n<tr>\n<td><strong>Number of Atoms</strong></td>\n<td width=\"312\"><strong>Prefix</strong></td>\n</tr>\n<tr>\n<td>1</td>\n<td>mono-</td>\n</tr>\n<tr>\n<td>2</td>\n<td>di-</td>\n</tr>\n<tr>\n<td>3</td>\n<td>tri-</td>\n</tr>\n<tr>\n<td>4</td>\n<td>tetra-</td>\n</tr>\n<tr>\n<td>5</td>\n<td>penta-</td>\n</tr>\n<tr>\n<td>6</td>\n<td>hexa-</td>\n</tr>\n<tr>\n<td>7</td>\n<td>hepta-</td>\n</tr>\n<tr>\n<td>8</td>\n<td>octa-</td>\n</tr>\n<tr>\n<td>9</td>\n<td>nona-</td>\n</tr>\n<tr>\n<td>10</td>\n<td>deca-</td>\n</tr>\n</tbody>\n</table>\n<p>You can attach the prefixes in the table above to any of the elements in a covalent compound, as exemplified by SO<sub>3</sub> (sulfur trioxide) and N<sub>2</sub>O (dinitrogen monoxide). The second element in each compound receives the &#8211;<em>ide</em> suffix, as in ionic compounds (which we discuss earlier in this chapter).</p>\n<p>In the case of covalent compounds, where cations or anions aren’t involved, the more electronegative element (in other words, the element that’s closer to the upper right-hand corner of the periodic table) tends to be named second.</p>\n<p>Finally, if the compound only has 1 atom for the first element you can leave off mono as the prefix. For example, you don’t call CO<sub>2</sub> monocarbon dioxide. Instead, you just call it carbon dioxide.</p>\n"},{"title":"Balancing reactions","thumb":null,"image":null,"content":"<p>Balancing chemical reactions can be a real challenge for some people. Sometimes just getting started is a real challenge. The example below shows how to balance a combustion reaction. There is a good chance that if you are here reading this you might be stuck on a combustion reaction, so make sure to read on. Even if not, this example is going to give you a solid idea of how to go about balancing any reaction you encounter.</p>\n<ol>\n<li>\n<p><strong>Start with the unbalanced reaction written out</strong>.</p>\n<p>C<sub>4</sub>H<sub>10</sub>(<em>g</em>) + O<sub>2</sub>(<em>g</em>) ®CO<sub>2</sub>(<em>g</em>) + H<sub>2</sub>O(<em>g</em>)</p>\n</li>\n<li>\n<p><strong>Balance the carbon atoms first</strong>.</p>\n<p>Remember: You want to wait until the end to balance hydrogen and oxygen atoms. You have 4 carbon atoms on the left and 1 carbon atom on the right, so put a coefficient of 4 in front of the carbon dioxide:</p>\n<p>C<sub>4</sub>H<sub>10</sub>(<em>g</em>) + O<sub>2</sub>(<em>g</em>) ® 4 CO<sub>2</sub>(<em>g</em>) + H<sub>2</sub>O(<em>g</em>)</p>\n</li>\n<li>\n<p><strong><strong>When all non-hydrogen and non-oxygen atoms are balanced, balance the hydrogen atoms.</strong></p>\n<p>Carbon is the only other atom in this example, so you can move on to hydrogen now. You have 10 hydrogen atoms on the left and 2 hydrogen atoms on the right, so use a coefficient of 5 in front of the water on the right:C<sub>4</sub>H<sub>10</sub>(<em>g</em>) + O<sub>2</sub>(<em>g</em>) ®4 CO<sub>2</sub>(<em>g</em>) + <strong>5</strong> H<sub>2</sub>O(<em>g</em>)</p>\n</li>\n<li>\n<p><strong>Balance the oxygen atoms</strong>.</p>\n<p>You have 2 oxygen atoms on the left and a total of 13 oxygen atoms on the right [(4 × 2) + (5 × 1) = 13]. What can you multiply 2 with in order for it to equal 13? How about 6.5?</p>\n<p>C<sub>4</sub>H<sub>10</sub>(<em>g</em>) + <strong>6.5</strong> O<sub>2</sub>(<em>g</em>) ®4 CO<sub>2</sub>(<em>g</em>) + 5 H<sub>2</sub>O(<em>g</em>)</p>\n</li>\n<li>\n<p><strong>Multiply all coefficients in the equation to get the lowest <em>whole-number</em> ratio of coefficients</strong>.</p>\n<p>For this example, multiply the entire equation by 2 (just the coefficients, please) in order to generate whole numbers:</p>\n<p>[C<sub>4</sub>H<sub>10</sub>(<em>g</em>) + 6.5 O<sub>2</sub>(<em>g</em>®4 CO<sub>2</sub>(<em>g</em>) + 5 H<sub>2</sub>O(<em>g</em>)] ×2</p>\n<p>Multiplying every coefficient by 2 (don’t touch the subscripts!) gives you</p>\n<p>2 C<sub>4</sub>H<sub>10</sub>(<em>g</em>) + 13 O<sub>2</sub>(<em>g</em>) ®8 CO<sub>2</sub>(<em>g</em>) + 10 H<sub>2</sub>O(<em>g</em>)</p>\n</li>\n<li>\n<p><strong>Check the atom count on both sides of the equation to ensure that the equation is balanced and the coefficients are in the lowest whole-number ratio</strong>.</p>\n</li>\n</ol>\n<p>This is a pretty complex example and hopefully it helps you out. Sometimes, though, all you might need to do is add a single coefficient of 2 or 3 in front of one compound. Just stay organized and keep things simple and you’ll be balancing reactions in no time!</p>\n"},{"title":"Extensive and intensive properties","thumb":null,"image":null,"content":"<p>There are all kinds of ways you can classify matter. One is to look at the different physical properties that that matter has. There are two major types of physical properties:</p>\n<ul>\n<li><strong>Extensive Properties:</strong> properties that depend on the amount of matter present\n<p>Examples: mass, volume, length, width or anything else that depends entirely on how much of the substance you have</li>\n<li><strong>Intensive Properties:</strong> properties that don’t depend on the amount of matter present\n<p>Examples: density, malleability, ductileness, hardness, melting point</li>\n</ul>\n<p>A helpful way to remember this is that intensive properties rely on what is “in”-side the matter, with the “in” signifying <em>intensive</em> and how it doesn’t matter how much of the matter is present.</p>\n<p>Extensive properties rely on the “ext”-erior of the matter, with the “ext” signifying <em>extensive</em> and the fact that now, the amount of what you see on the exterior of the matter does impact the property.</p>\n<p>Some physical properties are <em>extensive properties,</em> properties that depend on the amount of matter present. Mass and volume are extensive properties. A large chunk of gold has a larger mass and volume than a smaller chunk.</p>\n<p><em>Intensive properties,</em> however, don’t depend on the amount of matter present. Hardness is an intensive property. A large chunk of gold, for example, has the same hardness as a small chunk of gold. The mass and volume of these two chunks are different (extensive properties), but the hardness is the same.</p>\n<p>Intensive properties are especially useful to chemists because they can use intensive properties to identify a substance.</p>\n"}],"videoInfo":{"videoId":null,"name":null,"accountId":null,"playerId":null,"thumbnailUrl":null,"description":null,"uploadDate":null}},"sponsorship":{"sponsorshipPage":false,"backgroundImage":{"src":null,"width":0,"height":0},"brandingLine":"","brandingLink":"","brandingLogo":{"src":null,"width":0,"height":0},"sponsorAd":"","sponsorEbookTitle":"","sponsorEbookLink":"","sponsorEbookImage":{"src":null,"width":0,"height":0}},"primaryLearningPath":"Advance","lifeExpectancy":"Five years","lifeExpectancySetFrom":"2022-11-07T00:00:00+00:00","dummiesForKids":"no","sponsoredContent":"no","adInfo":"","adPairKey":[]},"status":"publish","visibility":"public","articleId":295575},{"headers":{"creationTime":"2018-04-24T01:43:18+00:00","modifiedTime":"2022-10-26T15:57:20+00:00","timestamp":"2022-10-26T18:01:02+00:00"},"data":{"breadcrumbs":[{"name":"Academics & The Arts","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33662"},"slug":"academics-the-arts","categoryId":33662},{"name":"Science","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33756"},"slug":"science","categoryId":33756},{"name":"Chemistry","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33762"},"slug":"chemistry","categoryId":33762}],"title":"How to Convert between Units Using Conversion Factors","strippedTitle":"how to convert between units using conversion factors","slug":"convert-units-using-conversion-factors","canonicalUrl":"","seo":{"metaDescription":"Learn how to quickly convert between measurement units using this handy conversion-factor chart and some simple algebra!","noIndex":0,"noFollow":0},"content":"A <em>conversion factor</em> uses your knowledge of the relationships between units to convert from one unit to another. For example, if you know that there are 2.54 centimeters in every inch (or 2.2 pounds in every kilogram or 101.3 kilopascals in every atmosphere), then converting between those units becomes simple algebra. It is important to know <a href=\"https://www.dummies.com/article/academics-the-arts/science/chemistry/chemistry-for-dummies-cheat-sheet-208625/\">some common conversions</a> of temperature, size, and pressure as well as metric prefixes.\r\n<h2 id=\"tab1\" >Conversion factor table</h2>\r\nThe following table includes some useful conversion factors.\r\n\r\n<img class=\"alignnone size-full wp-image-251837\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0501.jpg\" alt=\"CHEM_0501\" width=\"500\" height=\"708\" />\r\n\r\n \r\n<h2 id=\"tab2\" >Using conversion factors example</h2>\r\nThe following example shows how to use a basic conversion factor to fix non-SI units.\r\n\r\nDr. Geekmajor absentmindedly measures the mass of a sample to be 0.75 lb and records his measurement in his lab notebook. His astute lab assistant, who wants to save the doctor some embarrassment, knows that there are 2.2 lbs in every kilogram. The assistant quickly converts the doctor’s measurement to SI units. What does she get?\r\n\r\nThe answer is <strong>0.34 kg</strong>.\r\n\r\n<img class=\"alignnone size-full wp-image-251838\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0502.jpg\" alt=\"CHEM_0502\" width=\"201\" height=\"51\" />\r\n\r\nLet’s try another example. A chemistry student, daydreaming during lab, suddenly looks down to find that he’s measured the volume of his sample to be 1.5 cubic <em>inches.</em> What does he get when he converts this quantity to cubic centimeters?\r\n\r\nThe answer is <strong>25 cm<sup>3</sup></strong>.\r\n\r\n<img class=\"alignnone size-full wp-image-251839\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0503.jpg\" alt=\"CHEM_0503\" width=\"404\" height=\"63\" />\r\n\r\nRookie chemists often mistakenly assume that if there are 2.54 centimeters in every inch, then there are 2.54 cubic centimeters in every cubic inch. No! Although this assumption seems logical at first glance, it leads to catastrophically wrong answers. Remember that cubic units are units of volume and that the formula for volume is\r\n\r\n<img class=\"alignnone size-full wp-image-251840\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0504.jpg\" alt=\"CHEM_0504\" width=\"169\" height=\"23\" />\r\n\r\nImagine 1 cubic inch as a cube with 1-inch sides. The cube’s volume is\r\n\r\n<img class=\"alignnone size-full wp-image-251841\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0505.jpg\" alt=\"CHEM_0505\" width=\"164\" height=\"24\" />\r\n\r\nNow consider the dimensions of the cube in centimeters:\r\n\r\n<img class=\"alignnone size-full wp-image-251842\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0506.jpg\" alt=\"CHEM_0506\" width=\"211\" height=\"19\" />\r\n\r\nCalculate the volume using these measurements, and you get\r\n\r\n<img class=\"alignnone size-full wp-image-251843\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0507.jpg\" alt=\"CHEM_0507\" width=\"305\" height=\"24\" />\r\n\r\nThis volume is much greater than 2.54 cm<sup><span style=\"font-size: small;\">3</span></sup>! To convert units of area or volume using length measurements, square or cube everything in your conversion factor, not just the units, and everything works out just fine.","description":"A <em>conversion factor</em> uses your knowledge of the relationships between units to convert from one unit to another. For example, if you know that there are 2.54 centimeters in every inch (or 2.2 pounds in every kilogram or 101.3 kilopascals in every atmosphere), then converting between those units becomes simple algebra. It is important to know <a href=\"https://www.dummies.com/article/academics-the-arts/science/chemistry/chemistry-for-dummies-cheat-sheet-208625/\">some common conversions</a> of temperature, size, and pressure as well as metric prefixes.\r\n<h2 id=\"tab1\" >Conversion factor table</h2>\r\nThe following table includes some useful conversion factors.\r\n\r\n<img class=\"alignnone size-full wp-image-251837\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0501.jpg\" alt=\"CHEM_0501\" width=\"500\" height=\"708\" />\r\n\r\n \r\n<h2 id=\"tab2\" >Using conversion factors example</h2>\r\nThe following example shows how to use a basic conversion factor to fix non-SI units.\r\n\r\nDr. Geekmajor absentmindedly measures the mass of a sample to be 0.75 lb and records his measurement in his lab notebook. His astute lab assistant, who wants to save the doctor some embarrassment, knows that there are 2.2 lbs in every kilogram. The assistant quickly converts the doctor’s measurement to SI units. What does she get?\r\n\r\nThe answer is <strong>0.34 kg</strong>.\r\n\r\n<img class=\"alignnone size-full wp-image-251838\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0502.jpg\" alt=\"CHEM_0502\" width=\"201\" height=\"51\" />\r\n\r\nLet’s try another example. A chemistry student, daydreaming during lab, suddenly looks down to find that he’s measured the volume of his sample to be 1.5 cubic <em>inches.</em> What does he get when he converts this quantity to cubic centimeters?\r\n\r\nThe answer is <strong>25 cm<sup>3</sup></strong>.\r\n\r\n<img class=\"alignnone size-full wp-image-251839\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0503.jpg\" alt=\"CHEM_0503\" width=\"404\" height=\"63\" />\r\n\r\nRookie chemists often mistakenly assume that if there are 2.54 centimeters in every inch, then there are 2.54 cubic centimeters in every cubic inch. No! Although this assumption seems logical at first glance, it leads to catastrophically wrong answers. Remember that cubic units are units of volume and that the formula for volume is\r\n\r\n<img class=\"alignnone size-full wp-image-251840\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0504.jpg\" alt=\"CHEM_0504\" width=\"169\" height=\"23\" />\r\n\r\nImagine 1 cubic inch as a cube with 1-inch sides. The cube’s volume is\r\n\r\n<img class=\"alignnone size-full wp-image-251841\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0505.jpg\" alt=\"CHEM_0505\" width=\"164\" height=\"24\" />\r\n\r\nNow consider the dimensions of the cube in centimeters:\r\n\r\n<img class=\"alignnone size-full wp-image-251842\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0506.jpg\" alt=\"CHEM_0506\" width=\"211\" height=\"19\" />\r\n\r\nCalculate the volume using these measurements, and you get\r\n\r\n<img class=\"alignnone size-full wp-image-251843\" src=\"https://www.dummies.com/wp-content/uploads/CHEM_0507.jpg\" alt=\"CHEM_0507\" width=\"305\" height=\"24\" />\r\n\r\nThis volume is much greater than 2.54 cm<sup><span style=\"font-size: small;\">3</span></sup>! To convert units of area or volume using length measurements, square or cube everything in your conversion factor, not just the units, and everything works out just fine.","blurb":"","authors":[{"authorId":9160,"name":"Chris Hren","slug":"chris-hren","description":" <p><b>Christopher Hren</b> is a high school chemistry teacher and former track and football coach. <b>Peter J. Mikulecky, PhD,</b> teaches biology and chemistry at Fusion Learning Center and Fusion Academy. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9160"}},{"authorId":9161,"name":"Peter J. Mikulecky","slug":"peter-j-mikulecky","description":" <p><b>Christopher Hren</b> is a high school chemistry teacher and former track and football coach. <b>Peter J. Mikulecky, PhD,</b> teaches biology and chemistry at Fusion Learning Center and Fusion Academy. ","hasArticle":false,"_links":{"self":"https://dummies-api.dummies.com/v2/authors/9161"}}],"primaryCategoryTaxonomy":{"categoryId":33762,"title":"Chemistry","slug":"chemistry","_links":{"self":"https://dummies-api.dummies.com/v2/categories/33762"}},"secondaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"tertiaryCategoryTaxonomy":{"categoryId":0,"title":null,"slug":null,"_links":null},"trendingArticles":null,"inThisArticle":[{"label":"Conversion factor table","target":"#tab1"},{"label":"Using conversion factors example","target":"#tab2"}],"relatedArticles":{"fromBook":[{"articleId":253707,"title":"How to Make Unit Conversions","slug":"make-unit-conversions","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/253707"}},{"articleId":251010,"title":"How to Build Derived Units from Base Units","slug":"build-derived-units-base-units","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251010"}},{"articleId":251005,"title":"How to Do Arithmetic with Significant Figures","slug":"arithmetic-significant-figures","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251005"}},{"articleId":250992,"title":"How to Add and Subtract with Exponential Notation","slug":"add-subtract-exponential-notation","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/250992"}},{"articleId":250969,"title":"How to Multiply and Divide in Scientific Notation","slug":"multiply-divide-scientific-notation","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/250969"}}],"fromCategory":[{"articleId":253707,"title":"How to Make Unit Conversions","slug":"make-unit-conversions","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/253707"}},{"articleId":251010,"title":"How to Build Derived Units from Base Units","slug":"build-derived-units-base-units","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251010"}},{"articleId":251005,"title":"How to Do Arithmetic with Significant Figures","slug":"arithmetic-significant-figures","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/251005"}},{"articleId":250992,"title":"How to Add and Subtract with Exponential Notation","slug":"add-subtract-exponential-notation","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/250992"}},{"articleId":250969,"title":"How to Multiply and Divide in Scientific Notation","slug":"multiply-divide-scientific-notation","categoryList":["academics-the-arts","science","chemistry"],"_links":{"self":"https://dummies-api.dummies.com/v2/articles/250969"}}]},"hasRelatedBookFromSearch":false,"relatedBook":{"bookId":282070,"slug":"chemistry-workbook-for-dummies-with-online-practice-3rd-edition","isbn":"9781119357452","categoryList":["academics-the-arts","science","chemistry"],"amazon":{"default":"https://www.amazon.com/gp/product/1119357454/ref=as_li_tl?ie=UTF8&tag=wiley01-20","ca":"https://www.amazon.ca/gp/product/1119357454/ref=as_li_tl?ie=UTF8&tag=wiley01-20","indigo_ca":"http://www.tkqlhce.com/click-9208661-13710633?url=https://www.chapters.indigo.ca/en-ca/books/product/1119357454-item.html&cjsku=978111945484","gb":"https://www.amazon.co.uk/gp/product/1119357454/ref=as_li_tl?ie=UTF8&tag=wiley01-20","de":"https://www.amazon.de/gp/product/1119357454/ref=as_li_tl?ie=UTF8&tag=wiley01-20"},"image":{"src":"https://www.dummies.com/wp-content/uploads/chemistry-workbook-for-dummies-3rd-edition-cover-9781119357452-204x255.jpg","width":204,"height":255},"title":"Chemistry Workbook For Dummies with Online Practice","testBankPinActivationLink":"","bookOutOfPrint":false,"authorsInfo":"<p><b data-author-id=\"9160\">Christopher Hren</b> is a high school chemistry teacher and former track and football coach. <b data-author-id=\"9161\">Peter J. 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Anatomy Anatomy and Physiology All-in-One For Dummies Cheat Sheet

Cheat Sheet / Updated 03-08-2023

The human body is a beautiful and efficient system that everyone should know a little bit about. In order to study and talk about anatomy and physiology, though, you need to learn the language. You have to have a solid grasp on the directional terms, the body cavities, and the overall organization of the organs and their division of labor. A familiarity with common Latin and Greek word roots will go a long way too.

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Environmental Science What Causes Earthquakes?

Article / Updated 02-15-2023

An earthquake is the sometimes violent shaking of the ground caused by movements of Earth's tectonic plates. Most earthquakes occur along fault lines, which is where two tectonic plates come together. Earthquakes strike suddenly and violently and can occur at any time, day or night, throughout the year. Smaller earthquakes might crack some windows and shake products off store shelves, but larger earthquakes can cause death and massive destruction, devastating communities and debilitating local economies. A tectonic shift Earthquakes occur when large sections of the Earths' crust — called tectonic plates — shift. There are seven primary tectonic plates (African, Antarctic, Eurasian, Indo-Australian, North American, Pacific, and South American) and a number of smaller, secondary and tertiary plates. Because of underlying movement in the Earth's mantle, these plates can shift. This shifting of one plate causes it to rub against or push under or over an adjacent plate. The place where two plates meet is called a fault line, and it's at these fault lines that earthquakes occur. Earthquakes are often followed by smaller earthquakes called aftershocks, which can occur over days or weeks as the plates settle into equilibrium. In the United States, California experiences damaging earthquakes most often, but Alaska has the greatest number of large earthquakes. They occur mostly in uninhabited areas, though, and so don't cause as much damage. What can earthquakes do? The violent ground-shaking of earthquakes by itself can cause damage to homes, roads, and bridges; shake products off shelves; and lead to injuries and death, but earthquakes can also lead to other natural disasters: Avalanches and landslides: Earthquakes can shake snow, soil, and rock right off a sloped surface. Landslides have been a particular problem in California, where a number of mountainside homes have ended up in the Pacific Ocean because of them. Surface faulting: Surface faulting is a change in the relative positions of things on opposite sides of a fault line. For instance, a straight section of railroad track that runs across a fault line might have a nasty curve in it after an earthquake, rendering it useless for train travel. Tsunamis: Tsunamis are a series of waves that are caused by the sudden displacement of large amounts of ocean water, usually because of underwater earthquakes. When tsunamis hit land, they can knock over buildings, wash away cars, and cause massive flooding. The most massive tsunamis can reach heights of well over 500 feet. Liquefaction: Liquefaction occurs when water-logged soil acts like a liquid and causes sections of ground to sink or slide. As well as damage to roads and buildings, liquefaction can lead to flash floods. How are earthquakes measured? Seismometers and seismographs sense and record movements in the Earth's surface, showing both the intensity and duration of earthquakes and other tremors. Seismologists then use this information to rate the earthquake on the Richter scale. The Richter scale was developed in 1935 by Charles Richter to show the amount of energy released during an earthquake. It was originally intended not as an absolute measure of individual quakes but as a way to compare the relative strengths of different earthquakes. Though Richter measurements are generally thought of as being between 0 and 10, there are theoretically no limits to the scale in either direction. Earthquakes measuring less than 4.0 magnitude occur in small areas and might not even be noticed, much less cause any serious damage. Earthquakes measuring 4.0–4.9 magnitude cover a larger area. They are felt, but damage is light. You start to see some damage with a 5.0-magnitude earthquake, starting with poorly constructed buildings. Higher up on the Richter scale, you see greater damage over a greater area. The largest recorded earthquake was the 9.5-magnitude Great Chilean Earthquake of 1960. This quake spawned numerous tsunamis that caused damage as far away as Hawaii, Japan, and the Philippines.

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Physics String Theory and The Hierarchy Problem in Physics

Article / Updated 02-07-2023

Many physicists feel that string theory will ultimately be successful at resolving the hierarchy problem of the Standard Model of particle physics. Although it is an astounding success, the Standard Model hasn’t answered every question that physics hands to it. One of the major questions that remains is the hierarchy problem, which seeks an explanation for the diverse values that the Standard Model lets physicists work with. For example, if you count the theoretical Higgs boson (and both types of W bosons), the Standard Model of particle physics has 18 elementary particles. The masses of these particles aren’t predicted by the Standard Model. Physicists had to find these by experiment and plug them into the equations to get everything to work out right. You notice three families of particles among the fermions, which seems like a lot of unnecessary duplication. If we already have an electron, why does nature need to have a muon that’s 200 times as heavy? Why do we have so many types of quarks? Beyond that, when you look at the energy scales associated with the quantum field theories of the Standard Model, as shown in this figure, even more questions may occur to you. Why is there a gap of 16 orders of magnitude (16 zeroes!) between the intensity of the Planck scale energy and the weak scale? At the bottom of this scale is the vacuum energy, which is the energy generated by all the strange quantum behavior in empty space — virtual particles exploding into existence and quantum fields fluctuating wildly due to the uncertainty principle. The hierarchy problem occurs because the fundamental parameters of the Standard Model don’t reveal anything about these scales of energy. Just as physicists have to put the particles and their masses into the theory by hand, so too have they had to construct the energy scales by hand. Fundamental principles of physics don’t tell scientists how to transition smoothly from talking about the weak scale to talking about the Planck scale. Trying to understand the “gap” between the weak scale and the Planck scale is one of the major motivating factors behind trying to search for a quantum gravity theory in general, and string theory in particular. Many physicists would like a single theory that could be applied at all scales, without the need for renormalization (the mathematical process of removing infinities), or at least to understand what properties of nature determine the rules that work for different scales. Others are perfectly happy with renormalization, which has been a major tool of physics for nearly 40 years and works in virtually every problem that physicists run into.

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Chemistry Organic Chemistry II For Dummies Cheat Sheet

Cheat Sheet / Updated 01-09-2023

Organic Chemistry II is one of the toughest courses you can take. Surviving isn’t easy — you probably know that from your Organic Chemistry I class. Preparation is key: If you study the basics of organic chemistry the right way, prepare for your tests, and know your aromatic systems, you’re off to a great start!

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Environmental Science How Does Nuclear Fusion Work?

Article / Updated 01-05-2023

Nuclear fusion is essentially the opposite of nuclear fission. In fission, a heavy nucleus is split into smaller nuclei. With fusion, lighter nuclei are fused into a heavier nucleus. The fusion process is the reaction that powers the sun. On the sun, in a series of nuclear reactions, four isotopes of hydrogen-1 are fused into a helium-4 with the release of a tremendous amount of energy. Here on earth, two other isotopes of hydrogen are used: H-2, called deuterium, and H-3, called tritium. Deuterium is a minor isotope of hydrogen, but it’s still relatively abundant. Tritium doesn’t occur naturally, but it can easily be produced by bombarding deuterium with a neutron. The fusion reaction is shown in the following equation: Major breakthrough in 2022 In December 2022, scientists at the U.S. National Ignition Facility in Livermore, California, achieved a major breakthrough in nuclear fusion research: energy gain. Energy gain, also known in this context as ignition, means that they were able to create a fusion reaction that released more energy than they put in by their lab's gigantic high-powered lasers. The scientists said they proved nuclear fusion can work on Earth, but we are still many years from being able to use it in power plants. Yet, scientists are optimistic that controlled fusion power will be achieved. The rewards are great — an unlimited source of clean energy. Hydrogen bomb was first demonstration The first demonstration of nuclear fusion — the hydrogen bomb — was conducted by the military. A hydrogen bomb is approximately 1,000 times as powerful as an ordinary atomic bomb. The isotopes of hydrogen needed for the hydrogen bomb fusion reaction were placed around an ordinary fission bomb. The explosion of the fission bomb released the energy needed to provide the activation energy (the energy necessary to initiate, or start, the reaction) for the fusion process. Control issues with nuclear fusion The goal of scientists for the last 50 years has been the controlled release of energy from a fusion reaction. If the energy from a fusion reaction can be released slowly, it can be used to produce electricity. It will provide an unlimited supply of energy that has no wastes to deal with or contaminants to harm the atmosphere — simply non-polluting helium. But achieving this goal requires overcoming three problems: Temperature Time Containment Temperature The fusion process requires an extremely high activation energy. Heat is used to provide the energy, but it takes a lot of heat to start the reaction. Scientists estimate that the sample of hydrogen isotopes must be heated to approximately 40,000,000 K. K represents the Kelvin temperature scale. To get the Kelvin temperature, you add 273 to the Celsius temperature. Now 40,000,000 K is hotter than the sun! At this temperature, the electrons have long since left the building; all that’s left is a positively charged plasma, bare nuclei heated to a tremendously high temperature. Presently, scientists are trying to heat samples to this high temperature through two ways — magnetic fields and lasers. Neither one has yet achieved the necessary temperature. Time Time is the second problem scientists must overcome to achieve the controlled release of energy from fusion reactions. The charged nuclei must be held together close enough and long enough for the fusion reaction to start. Scientists estimate that the plasma needs to be held together at 40,000,000 K for about one second. Containment Containment is the major problem facing fusion research. At 40,000,000 K, everything is a gas. The best ceramics developed for the space program would vaporize when exposed to this temperature. Because the plasma has a charge, magnetic fields can be used to contain it — like a magnetic bottle. But if the bottle leaks, the reaction won’t take place. And scientists have yet to create a magnetic field that won’t allow the plasma to leak. Using lasers to zap the hydrogen isotope mixture and provide the necessary energy bypasses the containment problem. But scientists have not figured out how to protect the lasers themselves from the fusion reaction. Another Possible Use of Fusion An interesting by-product of fusion research is the fusion torch concept. With this idea, the fusion plasma, which must be cooled in order to produce steam, is used to incinerate garbage and solid wastes. Then the individual atoms and small molecules that are produced are collected and used as raw materials for industry. It seems like an ideal way to close the loop between waste and raw materials. Time will tell if this concept will eventually make it into practice.

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Biology Biology For Dummies Cheat Sheet

Cheat Sheet / Updated 12-23-2022

Biology is the study of the living world. All living things share certain common properties: They are made of cells that contain DNA. They maintain order inside their cells and bodies. They regulate their systems. They respond to signals in the environment. They transfer energy between themselves and their environment. They grow and develop; they reproduce. They have traits that have evolved over time.

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Physics How to Calculate a Spring Constant Using Hooke's Law

Article / Updated 12-23-2022

Any physicist knows that if an object applies a force to a spring, then the spring applies an equal and opposite force to the object. Hooke’s law gives the force a spring exerts on an object attached to it with the following equation: F = –kx The minus sign shows that this force is in the opposite direction of the force that’s stretching or compressing the spring. The variables of the equation are F, which represents force, k, which is called the spring constant and measures how stiff and strong the spring is, and x, the distance the spring is stretched or compressed away from its equilibrium or rest position. The force exerted by a spring is called a restoring force; it always acts to restore the spring toward equilibrium. In Hooke’s law, the negative sign on the spring’s force means that the force exerted by the spring opposes the spring’s displacement. Understanding springs and their direction of force The direction of force exerted by a spring The preceding figure shows a ball attached to a spring. You can see that if the spring isn’t stretched or compressed, it exerts no force on the ball. If you push the spring, however, it pushes back, and if you pull the spring, it pulls back. Hooke’s law is valid as long as the elastic material you’re dealing with stays elastic — that is, it stays within its elastic limit. If you pull a spring too far, it loses its stretchy ability. As long as a spring stays within its elastic limit, you can say that F = –kx. When a spring stays within its elastic limit and obeys Hooke’s law, the spring is called an ideal spring. How to find the spring constant (example problem) Suppose that a group of car designers knocks on your door and asks whether you can help design a suspension system. “Sure,” you say. They inform you that the car will have a mass of 1,000 kilograms, and you have four shock absorbers, each 0.5 meters long, to work with. How strong do the springs have to be? Assuming these shock absorbers use springs, each one has to support a mass of at least 250 kilograms, which weighs the following: F = mg = (250 kg)(9.8 m/s2) = 2,450 N where F equals force, m equals the mass of the object, and g equals the acceleration due to gravity, 9.8 meters per second2. The spring in the shock absorber will, at a minimum, have to give you 2,450 newtons of force at the maximum compression of 0.5 meters. What does this mean the spring constant should be? In order to figure out how to calculate the spring constant, we must remember what Hooke’s law says: F = –kx Now, we need to rework the equation so that we are calculating for the missing metric, which is the spring constant, or k. Looking only at the magnitudes and therefore omitting the negative sign, you get Time to plug in the numbers: The springs used in the shock absorbers must have spring constants of at least 4,900 newtons per meter. The car designers rush out, ecstatic, but you call after them, “Don’t forget, you need to at least double that if you actually want your car to be able to handle potholes.”

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Physics More Dimensions Make String Theory Work

Article / Updated 12-14-2022

For most interpretations, superstring theory requires a large number of extra space dimensions to be mathematically consistent: M-theory requires ten space dimensions. With the introduction of branes as multidimensional objects in string theory, it becomes possible to construct and imagine wildly creative geometries for space that correspond to different possible particles and forces. It’s unclear, at present, whether those extra dimensions exist or are just mathematical artifacts. The reason string theory requires extra dimensions is that trying to eliminate them results in much more complicated mathematical equations. It’s not impossible, but most physicists haven’t pursued these concepts in a great deal of depth, leaving science (perhaps by default) with a theory that requires many extra dimensions. From the time of Descartes, mathematicians have been able to translate between geometric and physical representations. Mathematicians can tackle their equations in virtually any number of dimensions that they choose, even if they can’t visually picture what they’re talking about. One of the tools mathematicians use in exploring higher dimensions is analogy. If you start with a zero-dimensional point and extend it through space, you get a one-dimensional line. If you take that line and extend it into a second dimension, you end up with a square. If you extend a square through a third dimension, you end up with a cube. If you then were to take a cube and extend into a fourth dimension, you’d get a shape called a hypercube. A line has two “corners” but extending it to a square gives four corners, while a cube has eight corners. By continuing to extend this algebraic relationship, a hypercube would be a four-dimensional object with 16 corners, and a similar relationship can be used to create analogous objects in additional dimensions. Such objects are obviously well outside of what our minds can picture. Humans aren’t psychologically wired to be able to picture more than three space dimensions. A handful of mathematicians (and possibly some physicists) have devoted their lives to the study of extra dimensions so fully that they may be able to actually picture a four-dimensional object, such as a hypercube. Most mathematicians can’t (so don’t feel bad if you can’t). Whole fields of mathematics — linear algebra, abstract algebra, topology, knot theory, complex analysis, and others — exist with the sole purpose of trying to take abstract concepts, frequently with large numbers of possible variables, degrees of freedom, or dimensions, and make sense of them. These sorts of mathematical tools are at the heart of string theory. Regardless of the ultimate success or failure of string theory as a physical model of reality, it has motivated mathematics to grow and explore new questions in new ways, and for that alone, it has proved useful.

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Chemistry Chemistry All-in-One For Dummies Cheat Sheet

Cheat Sheet / Updated 11-08-2022

Chemistry covers all kinds of stuff. Sometimes you might not be sure where to start when you are first given a set of problems and told to go forth and succeed. Sometimes it’s converting metric units, writing ionic formulas, naming covalent compounds, balancing reactions, or dealing with extensive and intensive properties. This Cheat Sheet is designed to give you some help on a few of the trickier things you might encounter so that when you are done looking it over you can go forth and succeed!

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Chemistry How to Convert between Units Using Conversion Factors

Article / Updated 10-26-2022

A conversion factor uses your knowledge of the relationships between units to convert from one unit to another. For example, if you know that there are 2.54 centimeters in every inch (or 2.2 pounds in every kilogram or 101.3 kilopascals in every atmosphere), then converting between those units becomes simple algebra. It is important to know some common conversions of temperature, size, and pressure as well as metric prefixes. Conversion factor table The following table includes some useful conversion factors. Using conversion factors example The following example shows how to use a basic conversion factor to fix non-SI units. Dr. Geekmajor absentmindedly measures the mass of a sample to be 0.75 lb and records his measurement in his lab notebook. His astute lab assistant, who wants to save the doctor some embarrassment, knows that there are 2.2 lbs in every kilogram. The assistant quickly converts the doctor’s measurement to SI units. What does she get? The answer is 0.34 kg. Let’s try another example. A chemistry student, daydreaming during lab, suddenly looks down to find that he’s measured the volume of his sample to be 1.5 cubic inches. What does he get when he converts this quantity to cubic centimeters? The answer is 25 cm3. Rookie chemists often mistakenly assume that if there are 2.54 centimeters in every inch, then there are 2.54 cubic centimeters in every cubic inch. No! Although this assumption seems logical at first glance, it leads to catastrophically wrong answers. Remember that cubic units are units of volume and that the formula for volume is Imagine 1 cubic inch as a cube with 1-inch sides. The cube’s volume is Now consider the dimensions of the cube in centimeters: Calculate the volume using these measurements, and you get This volume is much greater than 2.54 cm3! To convert units of area or volume using length measurements, square or cube everything in your conversion factor, not just the units, and everything works out just fine.

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