| A | B |
|---|
| ATMOSPHERE | The layers of gases that surround a planet |
| HUMIDITY | The amount of water vapor in a given volume of air. |
| AIR PRESSURE | The pressure caused by the weight of a column of air pushing down on an area. |
| BAROMETER | An instrument used to measure changes in air pressure. |
| Mercury Barometer | an instrument that measures air pressure consisting of a glass tube partially filled with mercury. |
| Aneroid Barometer | - an instrument that measures air pressure without using a liquid. Consists of an air-tight metal chamber that is sensitive to changes in air pressure. |
| WEATHER | condition of the atmosphere at a particular time and place |
| WATER VAPOR | Water in the gaseous state. |
| RELATIVE HUMIDITY | percentage of gaseous water in the air compared to the maximum it can hold |
| OZONE LAYER | Layer of the atmosphere containing high levels of ozone, a gas composed of molecules of O3 (three oxygen atoms bound together). Protects the planet from too much UV radiation. |
