Across
- 3. lighter element join together to form heavier elements is called what?
- 7. the largest land mass in earths history
- 9. the second longest period of time
- 14. the right age of something
- 15. the life force decreases over a sertant amount of time
- 16. big sheet of ice over mn
- 17. what happens when a star runs out of feul?
- 18. the formation of protons and neutrons
Down
- 1. happened to the earth five times
- 2. the biginning of the universe
- 4. the longest period of time
- 5. law of superposition
- 6. how to tell if an object is moving away from you
- 8. how to find the life expectancy of a star.
- 10. the death of a lot of species in a short time
- 11. small changes in temperature slowly
- 12. the shortest period of time
- 13. thought that the continents were puzzle pieces