Across
- 4. has always been on the Earth
- 6. the Earth is mostly made of
- 11. a purifying process
- 12. rocks, minerals and the ground
- 13. nature recycles matter through
- 14. causes cloud formation
- 15. carbon moves from living things to the atmosphere air that surrounds the Earth
- 16. bacteria that lives in the roots ofplants
- 18. where most of the nitrogen on Earth is
- 19. makes up 78% of the atmosphere
Down
- 1. water stored under the Earth
- 2. water on Earth is
- 3. all water on the Earth
- 5. a form used by plants
- 7. process where water moves above,on, and below
- 8. carbon moves from the air to the plants
- 9. all living organisms on Earth
- 10. carbon moves from plants to animals
- 17. used to fuel cars, power plants, and factories