Across
- 3. Many different species of land
- 6. lighter elements join together
- 8. how old the earth is
- 10. had a idea for continental drift
- 11. large number of speices disappearing in a short time.
- 13. The amount of time it takes for half of the radioactive atoms to decay.
- 14. Large ice sheet covered most of
- 16. divided into three ears
- 17. The universe got formed.
- 18. The bigger or smaller the star is
Down
- 1. at several different points in earth history all of the continents have been located close to each other.
- 2. moving towards or away from us
- 4. small changes that occur slowly
- 5. law of superposition
- 7. Huge sheets of ice called glaciers cover large parts of the earth.
- 9. Lasted 300 million years
- 12. As the earth began to cool down
- 15. The start runs out of fuel