Across
- 4. symbiotic bacteria in nitrogen fixation
- 5. 75% of earths surface \
- 6. 21% of the atmosphere
- 9. When water gets released from clouds
- 10. from sea to land
- 12. from land to sea
- 15. process where water vapour becomes liquid
- 17. dead organic substances are broken down
- 19. burning
- 21. O3
Down
- 1. relates to living organisms
- 2. organic material that forms when animals decay
- 3. 78% of the atmosphere
- 7. NO3
- 8. product of respiration
- 11. elemental form of carbon
- 13. relates to non living items
- 14. process of water turning into water vapour
- 16. material that covers most of earths surface
- 18. free living bacteria in nitrogen fixation
- 20. NO2