Across
- 1. A branch of science that focuses on Earth's crust and the history that shaped it
- 5. Made up of unstable atoms which give off atomic radiation
- 8. Older rocks on bottom newer on top
- 9. An organism that lived long ago
- 10. Exact age of a rock/fossil
Down
- 2. a single cell life form
- 3. people who study geology
- 4. How long it takes for half of something to decay into another thing
- 6. Half life is 5,730 years
- 7. The age of something compared to another