Nitrogen Cycle

2. Bacteria that converts nitrates back into nitrogen gas
4. Most abundant gas in the atmosphere (2 words)
5. When decomposers break down dead organic matter and return nitrogen to the soil
6. vast reservoir of N2 that makes up 80% of Earth's atmosphere (2 words)
7. A salt of a certain unstable nitrogen-containing acid
10. Also known as the dead zone, an area with low dissolved oxygen levels
13. This is caused when an infant's blood lacks enough oxygen; often causing bluish-colored skin (3 words)
15. When microorganisms use available nitrates, making them unavailable for plants
16. An ion that is easily used by plants, but can leach from soil
17. excessive enrichment of a body of water
18. Plant organism involved in Nitrogenfixation The process in which atmospheric N2 is converted into ammonia by lightning (2 words)
19. Process by which plants incorporate nitrogen compounds from their environment into their own organic molecules

1. Conversion of N2 into ammonia by bacteria or lightning (2 words)
3. This microorganism converts N2 into usable forms (3 words)
4. Nonmetallic element with the atomic number 7
8. Two-step biological process that involves soil bacteria
9. A consequence of human disruption to the nitrogen cycle, through emissions of nitrogen oxides (2 words)
11. Inorganic compound formed from N2
12. An organism that breaks down organic matter
14. Primary medium where much of the Nitrogen Cycle processes take place