Across
- 1. a scale
- 3. ph 6-1
- 6. summary
- 7. earths outer layer
- 9. being eroded by wind, water, or other natural agents
- 11. a long and distinct period of history.
- 13. solid liquid gas
- 14. a person who studies rocks
- 16. from water to gas
- 18. lightest element
- 19. 2 things combined
- 21. over 100 substances
Down
- 1. lasted 289 million years
- 2. remains of a dead organism millions of years ago
- 4. earths inner layer
- 5. gas to liquid
- 8. transported from its source and deposited in water.
- 10. ph 7
- 12. ph 8-13
- 15. liquid to gas
- 17. questioning what will happen
- 20. the 2nd element