Across
- 3. it constists of 71% of the earth's surface
- 5. it is the building blocks of matter
- 8. Different species of organism that lives together in any given area
- 11. introduced the idea of protoplanet hypothesis
- 12. The habituable zone
- 17. introduced dust and gases
- 19. boundary between crust and mantle
Down
- 1. suggested Venus-Mercury and Earth- Mars were formed this way
- 2. It is the boundary between troposphere and stratosphere
- 4. examples of this are sun, earth's core
- 6. it is 0.09% of the atmosphere
- 7. Considered as closed system
- 9. it is the collection of ecosystem
- 10. basic unit of life
- 13. it creates magnetic field that protects the earth from the sun
- 14. all biotic and abiotic factors are here
- 15. fastest planet
- 16. it is 50-85km high up; slows down meteor
- 18. ice giant