Across
- 2. Adenosine ________ ; energy produced by living organisms
- 5. What covers the majority of the atmosphere
- 9. A bacteria that helps in the nitrogen cycle
- 12. Unburnt carbon substance
- 13. A process of both water and carbon cycle
- 14. A type of plant whose seed contains two cotyledons
- 17. Majority of the atmosphere of Venus and Mars
- 18. Percentage of oxygen in the atmosphere
- 19. A poisonous gas located high in the atmosphere
- 21. Living things on earth
Down
- 1. A form of carbon
- 3. The majority of water on earth
- 4. A fossil fuel
- 6. The process of formation of NO₃
- 7. The process of formation of NH₃
- 8. One of the main causes of pollution
- 10. Visibility-reducing pollution
- 11. A substance that causes soil and water pollution
- 15. A type of gas in the atmosphere
- 16. It helps in preventing soil erosion
- 20. Decayed living organisms in soil