States of Matter
- Solid - Solids have a definite size and shape. Particles are close together, and vibrate.
- Liquid - Liquids do not have a fixed shape. Particles take the shape of their container. Particles are further apart, and can move freely.
- Gas - Gases do not have a fixed shape. Particles take the shape of their container. Particles are far apart, and move very freely.
Changes of State
- Melting - the change of state from solid to liquid
- Freezing or Solidification - the change of state from liquid to solid
- Boiling or Evaporation - the change of state from liquid to gas
- Condensation - the change of state from gas to liquid
- Sublimation - the change of state directly from gas to solid, and vice versa (e.g. of carbon dioxide gas or carbon dioxide solid 'dry ice')
Melting and Boiling Points
- Melting Point - the temperature at which matter changes from solid to liquid, and vice versa (e.g. The melting point of water from ice to liquid water is 0 °C)
- Boiling Point - the temperature at which matter changes from a liquid to a gas, and vice versa (e.g. The boiling point of water from liquid water to steam is 100 °C)
| CHEMICAL NAME | MELTING POINT (°C) |
BOILING POINT (°C) |
STATE AT ROOM TEMPERATURE |
| Helium | –272 °C | –269 °C | gas |
| Hydrogen | –259 °C | –252 °C | gas |
| Oxygen | –218 °C | –183 °C | gas |
| Nitrogen | –210 °C | –195 °C | gas |
| Ethanol (Alcohol) | –114 °C | 79 °C | liquid |
| Water | 0 °C | 100 °C | liquid |
| Common Salt | 804 °C | 808 °C | solid |
| Copper | 1083 °C | 2567 °C | solid |
| Iron | 1535 °C | 2750 °C | solid |
| Tungsten | 3410 °C | 5660 °C | solid |