| A | B |
|---|
| nitrogen cycle | how nitrogen in the atmosphere is maintained |
| amount of nitrogen in the atmosphere | 78% |
| amount of oxygen in the atmosphere | 21% |
| bacteria | how nitogen is removed from the atmosphere |
| photosynthesis | the process of plants using sunlight carbon dioxide and water to produce oxygen and sugar |
| water vapor | water that has evaporated from lakes, oceans, streams and soil forming an invisible gas |
| the amount of water in dry air | <1% |
| the amount of water in moist air | as much as 4% |
| ozone | absorbs UV rays in the stratosphere |
| Chloroflorocarbons | molecules that were found in refridgerators, and air conditioners that destroy the ozone layer. |
| particulates | solid particles found in the atmosphere |
| atmospheric pressure | the pressure exerted on the surface by the atmosphere |
| gravity | holds the gases of the atmosphere near the surface of the earth. |
| standard atmospheric pressure | 1 atmosphere, 760mm Hg, or 1000 millibars |
| mercurial barometer | a barometer where atmospheric pressure presses on liquid mercury in a well at the base. |
| aneroid barometer | a sealed metal container which has most of the air removed to forma partial vaccuum. Can be an altimeter. |
| troposphere | lowest level of the atmosphere where weather happens. |
| stratosphere | second layer of the atmosphere where temperature increases as altitude increases. |
| mesosphere | Third layer of the atmosphere where temperature decreases as altitude increases. |
| thermosphere | Highest layer of the atmosphere where temperatures can reach as hot as 1000 degrees. Where the auroras are located. |
| air polllution | anysubstance in the atmosphere that is harmful to humans. |
| smog | smoke and fog |
| temperature inversion | layering of warm air on top of cool air. |
