Across
- 2. Endoskeleton and Exoskeleton of various animals are made up of ______ salts
- 7. Diamonds have carbon in ______ form
- 8. Oxygen is returned to atmosphere by this one major process
- 9. it converts Nitrogen into oxides of nitrogen
Down
- 1. life forms that cannot tolerate high amount of dissolved salts in saline water
- 3. acids
- 4. part of many molecules essential to life
- 5. fossil fuels contain small amount of Nitrogen and_______
- 6. absorbs harmful UV radiation of sun