Science World

3. – bacteria convert ammonia to nitrites (NO₂⁻) and nitrates (NO₃⁻)
7. – phosphate settles in oceans forming new rocks
9. –absorption of nutrients by an organism.
13. fixation – bacteria or lightning convert atmospheric N₂ into ammonia (NH₃) or ammonium (NH₄⁺)
14. (Mineralization) – decomposition releasing ammonia from organic matter
15. – water stored underground in aquifers

1. – movement of rock layers bringing nutrients back to surface
2. – flow of water into the ground to recharge aquifers
4. – conversion of nitrates back to atmospheric N₂ gas
5. – evaporation of water from plant leaves
6. effect – increase in Earth’s temperature from trapped heat by CO₂ and other gases
8. – bacteria temporarily lock up nitrogen for their own use
10. – surface flow of water due to gravity
11. fuels – long-term carbon storage from buried organic material (coal, oil, natural gas)
12. – layer of rock or sediment holding groundwater