| Term | Definition |
|---|---|
| Altitude | Vertical distance, or elevation, above sea level. |
| Boil | Change from a liquid to a gas |
| Boiling Point | The temperature at which boiling occurs |
| Freeze | Change from a liquid to a solid |
| Freezing point | The temperature at which freezing occurs |
| Gas | A phase in which matter has no definite shape or volume |
| Gas properties | Will expand to fill any container; can be compressed; molecules relatively far apart and move freely. |
| Water vapor | Water in the gas phase |
| Liquid | A phase in which matter has no definite volume but no definite shape. |
| Liquid properties | Will take the shape of a container but cannot expand or be compressed; molecules in a liquid move randomly but stay close to one another |
| Melt | Change from a solid to a liquid |
| Meting point | The temperature at which melting occurs. |
| Phase | A state of matter with certain physical propeties. |
| Solid | A phase in which matter has a definite shape and a definite volume |
| Solid properties | Will retain the same shape and volume in any container ; atoms are held in a rigid structure and cannot move freely |
| Ice | Water in the solid phase |
| Thermal Energy | Energy in the form of heat |
| Vaporization | Rapid change from liquid to gas |
| Condensation | Change from gas to liquid |
| Sublimation | Change from solid to gas |
| Evaporation | Slow change from liquid to gas |
| Deposition | Change from gas to solid |
