| A | B |
|---|
| troposphere | located nearest the Earth's surface, contains smog and clouds |
| doldrums | windless zones near the equator |
| What happens to evaporated water? | condenses, forming clouds |
| radiation | transfer of energy by electromagnetic waves |
| ionosphere | contains electrically charged particles that reflect radio waves at night |
| exosphere | merges into outer space |
| ultraviolet radiation | may cause skin cancer |
| equator | air above it is heated more than other places |
| reflection and absorbtion | prevents some radiation from reaching the Earth's surface |
| thermosphere | temperatures are very warm |
| water | can be liquid, solid or gas |
| smog | a mixture of pollutants, oxygen formed in sunlight; harms plants and lungs |
| water vapor | makes up zero to four% of air |
| oxygen | makes up 21% of atmosphere |
| ozone | usually found in the upper stratosphere, protects us from too much UV radiation |
| chlorofluorocarbons | chemicals that can destroy the ozone layer |
| air pressure | greatest at sea level, more molecules pushing done |
