Covalent Bonds: Types of Chemical Formulas
There are several types of chemical formulas that you can use to represent chemical bonds. These include empirical formulas, molecular (or true) formulas, and structural formulas. [more…]
The Unusual Properties of Water Molecules
Water molecules have unusual chemical and physical properties. Water can exist in all three states of matter at the same time: liquid, gas, and solid.
Imagine that you’re sitting in your hot tub [more…]
Reactants and Products in Chemical Reactions
In a chemical reaction, substances (elements and/or compounds) called reactants are changed into other substances (compounds and/or elements) called products [more…]
Collision Theory: How Chemical Reactions Occur
In order for a chemical reaction to take place, the reactants must collide. The collision between the molecules in a chemical reaction provides the kinetic energy needed to break the necessary bonds so [more…]
The Common Types of Chemical Reactions
Several general types of chemical reactions can occur based on what happens when going from reactants to products. The more common types of chemical reactions are as follows: [more…]
How to Balance Chemical Reactions in Equations
When you write an equation for a chemical reaction, the two sides of the equation should balance — you need the same number of each kind of element on both sides. If you carry out a chemical reaction and [more…]
What Factors Affect the Speed of Chemical Reactions?
Kinetics is the study of the speed of a chemical reaction. Some chemical reactions are fast; others are slow. Sometimes chemists want to speed the slow ones up and slow the fast ones down. [more…]
Redox Reactions: Oxidation and Reduction
Redox reactions — reactions in which there’s a simultaneous transfer of electrons from one chemical species to another — are really composed of two different reactions: [more…]
Rules for Assigning Oxidation Numbers to Elements
Oxidation numbers are bookkeeping numbers. They allow chemists to do things such as balance redox (reduction/oxidation) equations. Oxidation numbers are positive or negative numbers, but don’t confuse [more…]
How to Balance Redox Equations
Redox equations are often so complex that fiddling with coefficients to balance chemical equations doesn’t always work well. Chemists have developed an alternative method [more…]
Electrochemical Cells: The Daniell Cell
Many of the things we deal with in life are related either directly or indirectly to electrochemical reactions. The Daniell cell is an electrochemical cell named after John Frederic Daniell, the British [more…]
Electrochemical Cells: Flashlight Cells
The common flashlight cell, a dry electrochemical cell, is contained in a zinc housing that acts as the anode (the electrode at which oxidation takes place). The other electrode, the cathode [more…]
Electrochemical Cells: Automobile Batteries
The automobile battery, or lead storage battery, consists of six electrochemical cells connected in series. The anode of each cell is lead, while the cathode is lead dioxide. [more…]
How the Electroplating Process Works
Electrolytic cells, cells that use electricity to produce a desired redox reaction, are used extensively in our society, for processes such as electroplating and electrolysis. [more…]
Combustion Reactions of Fuels and Foods
Combustion reactions of fuels and foods are types of redox reactions that are essential for life and civilization — because heat is the most important product of these reactions. [more…]
The Periodicity of Chemical Elements
A pattern of repeating order is called periodicity. In the mid-1800s, Dmitri Mendeleev, a Russian chemist, noticed a repeating pattern of chemical properties in elements. [more…]
The Periodic Table: Metals, Nonmetals, and Metalloids
Using the periodic table, you can classify the elements in many ways. One useful way is by metals, nonmetals, and metalloids. Most of the elements on the periodic table are classified as metals. [more…]
Electronegativity and Polar Covalent Bonding
Electronegativity is the strength an atom has to attract a bonding pair of electrons to itself. When a chlorine atom covalently bonds to another chlorine atom, the shared electron pair is shared equally [more…]
What Are Stem Cells?
You’ve probably heard about stem cells in the news and may wonder exactly what that scientific term means. Stem cells are the body’s master cells. Stem cells can renew themselves [more…]
Explore Current Stem Cell Treatments
Scientists have been working with human adult stem cells — the stem cells found in specific tissues — for more than 40 years, compared to only a dozen years for human embryonic stem cells. As a result, [more…]
Stem Cell Research for Patient Treatment Plans
Stem cell scientists use stem cells to understand normal cell physiology, cell function, and development, as well as the mechanisms and progression of various diseases. Scientists hope to use this valuable [more…]
Stem Cells For Dummies Cheat Sheet
Scientists use various types of stem cells in the lab to gain a better understanding of how normal human development works and to look for new methods of treating a wide range of devastating human ailments [more…]
Important Parts of Eukaryotic Cells
All eukaryotic cells have organelles, a nucleus, and many internal membranes. These components divide the eukaryotic cell into sections, with each specializing in different functions. Each function is [more…]
Cellular Respiration in Molecular Biology
Cellular respiration is your body's way of breaking down food molecules (carbohydrates, proteins, and fats) and making their stored energy available to the cell. Here's a brief overview: [more…]
Four Groups of Macromolecules
Macromolecules are just that - large molecules. The four groups of macromolecules, shown in the table below, are essential to the structure and function of a cell. [more…]
