| A | B |
|---|
| weather | The condition of Earth's atmosphere at a particular time and place. |
| atmosphere | The envelope of gases that surrounds Earth. |
| ozone | A form of oxygen that has three oxygen atoms in each molecule instead of the usual two. |
| water vapor | Water in the form of gas. |
| density | The amount of mass of a substance in a given volume. |
| air pressure | The pressure caused by the weight of a column of air. |
| pressure | The amount of force pushing on an area. |
| barometer | An instrument used to measure changes in air pressure. |
| aneroid barometer | An instrument that measures the changes in air pressure without using a liquid. |
| altitude | Elevation above sea level. |
