Across
- 1. rocks age compared to the rocks around it
- 3. large span of time
- 5. number of years since the rocked formed
- 8. that said earths continents were not always in their current locations
- 10. divisions of time
- 12. elements join together to form heavier elements
- 13. get longer or shorter
- 15. amount of time it takes for only half the atoms to decay
Down
- 1. rising quickly
- 2. being located close to each other
- 4. either a red giant or super giant
- 6. sheets of ice covered earths surface
- 7. hydrogen and helium
- 9. numbers of species disappearing
- 11. of lakes were formed from glaciers
- 12. divisions of time
- 14. rapidly