| A | B |
|---|
| air pressure | the push of air against its surroundings |
| barometer | the device used to measure air pressure |
| high-pressure areas | areas where pressure is higher than the surrounding air |
| low-pressure areas | areas where pressure is lower than the surrounding air |
| wind vane | device used to find wind directions |
| windsock | a cloth bag open at both ends with one end being more narrow than the other end that is used to find wind direction |
| anemometer | a device used to measure wind speed |
| humidity | the amount of water vapor in the air |
| relative humidity | the amount of water vapor the air is holding at a given temperature compared to the total amount that it could hold at that temperature |
| evaporate | water changes from a liquid to a gas |
| condenses | water vapor changes from a gas to a liquid; this process is also called condensation |
| cloud | billions of tiny drops of water that have condensed from the air |
| precipitation | any form of water that falls from the air to the Earth's surface |
| rain gauge | a device used to measure the amount of precipitation |
| sea level | where particles of air are the closest |
| wind | can be used as a source of energy to power turbines which produce electricity |
| closer | cooling air causes particles of air to move |
| higher | cooling air causes air to move closer together and causes the air pressure to be |
| farther | air particles are ...... apart when you are high up in a mountain |
| lower | when you are in the mountains the air pressure is .... because air particles are farther apart |
| oxygen | If air is farther apart, you have less air particles of ... |
| water vapor | hot, humid air contains a great deal of ... |
| hotter | If it is humid, your sweat cannot evaporate quickly, so you feel ... |
| rain forms | water evaporates forming water vapor; water vapor condenses to form clouds; drops in the clouds grow larger and heavier; the drops fall to Earth. |
