Across
- 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
Down
- 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