| A | B |
|---|
| Atmosphere | Layer of air that surrounds Earth |
| Altitude | Distance above sea level |
| Density | amount of mass in a given volume of a substance |
| 21% | amount of oxygen in the atmosphere |
| 78% | Amount of nitrogen in the atmosphere |
| cycles | processes that repeat over and over |
| carbon cycle | exchange of carbon dioxide and oxygen in atmosphere |
| Sudden changes | Volcanic eruptions, Forest Fires, Dust Storms |
| Radiation | energy that travels distance in waves |
| Earth's surface | absorbs 50% and reflects 5% of radiation |
| Clouds | absorbs 20% and reflects 25% of radiation |
| Conduction | transfer of energy by direct contact |
| Convcection | transfer of energy by motion of gas or liquid |
| Stratosphere | where ozone is located |
| Mesosphere | where most meteors burn up |
| Troposphere | contains about 80% of the atmosphere |
| Troposphere | where the greenhouse gases are located |
| ultraviolet radiation | dangerous;more energy than visible light |
| infrared radiation | less energy than visible light |
| infrared radiation | warms materials that absorb it |
| ultraviolet radiation | can cause sunburn |
| ozone | made up of 3 oxygen atoms |
| ozone | absorbs ultraviolet radiation |
| greenhouse effect | process that heats the Earth |
| greenhouse gases | Carbon Dioxide, methane, water vapor and other gases that absorb and give off infrared radiation |
| air pollution | smoke and other harmful materials that are added to the air |
| Particulates | tiny particles or droplets that are mixed with the air |
| Fossil fuels | fuels that are formed by the remains of prehistoric animals and plants |
| smog | the combination of smoke and fog |
| smog | sunlight causes fumes from gas, car exhaust, and other gases to react chemically |
| carbon dioxide | comes from the burning of fossil fuels |
| methane | comes from livestock, bacteria in rice fields, landfills |
| nitrous oxide | comes from fertilizers and chemical factories |
