Unit 3:Lesson 2

3. the process through which cells convert sugars into energy using oxygen
4. the process that changes atmospheric nitrogen
8. the cycle in which oxygen is converted into CO2
11. the process by which living things decompose (rot) when they die
12. there process in which CO2 travels from the atmosphere into living things and the earth and then back into the atmosphere

1. water that falls from the clouds to Earth's surface
2. describes the existence and movement of water
5. the gas formed when carbon is burned or when people or animals breathe it out
6. the process during which water vapor changes into liquid water
7. fires, burning fossil fuels, or explosions
9. the process during which liquid water changes into a gas called water vapor
10. how nitrogen moves between plants, animals, bacteria, the atmosphere, and soil