| A | B |
|---|
| weight of air pushing down on us | pressure |
| tightly packed air molecules | density |
| toxic pollutant in smog | ozone (bad) |
| protects us from harmful UV/ultraviolet radiation | ozone layer |
| a form of oxygen with three molecules | ozone |
| could be caused by increases in CO2 | global warming |
| heat trapped near Earth's surface by CO2 | greenhouse effect |
| thick, brownish haze of air pollution over cities | photochemical smog |
| chemicals causing a hole in ozone layer | CFC's |
| gas comprising 78% of our atmoshpere | nitrogen |
| gas comprising 21% of our atmosphere | oxygen |
| layer of gases surrounding our planet | atmosphere |
| pollutants (oxides) react with water vapor | acid rain |
