| A | B |
| solid | the state of matter in which materials have a definite shape and definite volume |
| liquid | the state of matter in which a material has a definite volume but not a definite shape |
| gas | the state of matter in which a material has neither a definite shape nor a definite volume |
| kinetic energy | the energy an object has due to its motion |
| pressure | the result of a force distributed over an area |
| absolute zero | a temperature of 0 kelvins |
| Charles's law | the direct proportion of the volume of a gas to its temperture (in kelvins) if the pressure and the number of particles of the gas are constant |
| Boyle's law | the inverse variation of the volume of a gas with its pressure if the temperature and the number of particles are constant |
| phase change | a reversible physical change that occurs when a substance changes from one state of matter to another |
| endothermic | a description of a change in which a system absorbs energy from its surroundings |
| heat of fusion | the energy a substance must absorb in order to change from a solid to a liquid |
| exothermic | a description of a change in which a system releases energy to its surroundings |
| vaporization | the phase change in which a substance changes from a liquid into a gas |
| heat of vaporization | the energy a substance must absorb in order to change from a liquid to a gas |
| evaporation | the process that changes a substance from a liquid to a gas at temperatures below the substance's boiling point |
| vapor pressure | the pressure caused by the collisions of particles in a vapor with the walls of a container |
| condensation | the phase change in which a substance changes from a gas or vapor to a liquid |
| sublimation | the phase change in which a substance changes from a solid to a gas or vapor without changing into a liquid first |
| deposition | the phase change in which a gas or vapor changes directly into a solid without first changing into a liquid |