| A | B |
|---|
| Condensation | the process where water vapor changes to water droplets in the atmosphere. |
| Dew | moisture that forms when water vapor condenses directly onto a surface. |
| Evaporation | the process where energy from the sun causes water to change from a liquid to a gas. |
| Frost | moisture that forms when water vapor changes from gas directly to ice crystals on a surface. |
| Greenhouse effect | the natural heating that occurs when certain gases in Earth’s atmosphere trap heat. |
| Groundwater flow | the process by which water flows underground. |
| Infiltration | the process by which water on the ground surface enters the soil. |
| Ozone | a form of oxygen that absorbs harmful radiation from the sun. |
| Precipitation | water falling from clouds whose form is determined by air temperature. |
| Surface runoff | water that flows across earth’s surface to reach rivers, lakes, or oceans. |
| Transpiration | the process where plants release water vapor to the atmosphere through openings in their leaves called stomata. |
| Water cycle | the cycle of processes by which water circulates between the earth's oceans, atmosphere, and land. |
| Greenhouse gases | atmospheric gases such as carbon dioxide, methane, and water vapor that contribute to the greenhouse effect. |
| Trace gases | small amounts of gases in earth’s atmosphere. |
| Air pressure | the force exerted onto a surface by the weight of the air. |
