The answers to ACT Science Test questions come mostly from information in the passages, but every once in a while, you'll encounter a question that requires you to conjure up a scientific term or rule you learned in middle school.
Refresh your memory with this short glossary of science basics.
| Scientific Term | Definition |
|---|---|
| Acceleration | The rate of change in velocity |
| Allele | A gene variant |
| Atom | A particle that contains protons, neutrons, and electrons and is the smallest part that can be involve in a chemical reaction |
| Boiling point | The temperature when a liquid becomes a gas |
| Buoyancy | The ability of an object to float |
| Cell | The smallest independent element of an organism |
| Charge | The either positive or negative amount of unbalanced energy |
| Chemical reaction | The rearrangement of atoms to form new substances |
| Chromosomes | The structure of nucleic acids and proteins that carries the genetic material in a cell |
| Compound | A substance made up of more than one element |
| Conduction | Heat transfer as a result of molecular interaction |
| Constant | The elements of an experiment that are controlled to remain the same |
| Control group | The group in an experiment that provides a standard for comparison because it doesn't receive the independent variable |
| Convection | Heat transfer as a result of fluid movement |
| Density | The mass per volume in a substance |
| Dependent variable | The variable in an experiment that changes as a result of effect of the independent variable |
| Elasticity | The ability of a substance to return to its original shape |
| Electrons | Negatively charged atomic particles |
| Element | A substance comprised of atoms with the same atomic number and cannot be split into smaller substances |
| Fluid | A liquid or gas |
| Gamete | A sex cell that carries the genes of both parents |
| Gene | A section of DNA that determines inheritance |
| Gravity | The force that attracts an object toward the center of the earth |
| Hypothesis | The prediction of how the independent variable in an experiment will affect the dependent variable |
| Independent variable | The variable controlled by the experimenter |
| Inertia | The tendency of a body to remain at rest |
| Ion | Atom with an unbalanced electrical charge due to a loss or gain of electrons |
| Kinetic energy | The energy of a body in motion |
| Mass | The quantity of a body's matter |
| Molecule | A group of bonded atoms |
| Neutrons | Particles with zero charge |
| Nucleus | The part of the atom that contains protons and neutrons |
| Potential energy | The amount of useable energy a body has when it's not moving |
| Protons | Particles with a positive energy charge |
| Radiation | Transfer of energy as waves or rays |
| Reactants | The substances that participate in a chemical reaction |
| Variables | The elements of an experiment that change or could change |
| Velocity | The rate of change in distance with respect to time |