Natural resources
Across
- 3. the layer below stratosphere
- 5. Nitrogen —> nitrite and nitrate
- 6. cycling of matter and transfer of energy
- 10. nitrogen gets converted to this when animal dies
- 12. used for precipitation
- 14. product of photosynthesis
- 17. atomic no.6
- 18. process that warms earth
- 19. home for marine life
- 20. fast moving air
Down
- 1. process of using oxygen for breaking down food
- 2. wonder liquid
- 4. NO2
- 7. falls down as rain containing sulphuric dioxide and oxides of nitrogen
- 8. NO3
- 9. a type of greenhouse gas
- 11. plants absorb minerals from this
- 13. Part of earth not covered in water
- 15. atomic no.7
- 16. Collectively plants, animals and landscapes