| A | B |
|---|
| states of matter | the physical forms in which a substance can exist; states include solid, liquid, gas, and plasma |
| solid | the state in which matter has a definite shape and volume |
| liquid | the state in which matter takes the shape of its container and has a definite volume |
| gas | the state in which matter changes in both shape and volume |
| surface tension | the force on the particles at the surface of a liquid that causes the liquid to form spherical drops |
| viscosity | a liquid's resistance to flow |
| pressure | the amount of force exerted on a given area; expressed in pascals (Pa) |
| Boyle's law | the law that states that for a fixed amount of gas at a constant temperature, the volume of a gas increases as its pressure decreases |
| Charles's law | the law that states that for a fixed amount of gas at a constant pressure, the volume of a gas increases as its temperature increases |
| plasma | the state of matter that does not have definite shape or volume and whose particles have broken apart; plasma is composed of electrons and positively charged ions |
| change of state | the conversion of a substance from one physical form to another |
| endothermic | the term used to describe a physical or a chemical change in which energy is absorbed |
| exothermic | the term used to describe a physical or a chemical change in which energy is released or removed |
| freezing | the change of state from a liquid to a solid |
| freezing point | the temperature at which a liquid changes into a solid |
| melting | the change of state from a solid to a liquid |
| melting point | the temperature at which a substance changes from a solid to a liquid |
| boiling | vaporization that occurs throughout a liquid |
| boiling point | the temperature at which a liquid boils and becomes a gas |
| evaporation | vaporization that occurs at the surface of a liquid below its boiling point |
| condensation | the change of state from a gas to a liquid |
| condensation point | the temperature at which a gas becomes a liquid |
| sublimation | the change of state from a solid directly into a gas |
