Answer:
1. Radioactive dating
2. Unstable elements
3. Decay products
4. The amount of time for half of the isotope to change into the decay product
5. By comparing the amount of decay product with the amount of original isotope found in the rock
6. Carbon-14 isotopes
7. Uranium-238
8. The half-life of Carbon-14 is too short
9. Fossils don't contain the original isotope (Uranium-238)
Explanation:
The text has the answers in order of the questions, you just need to look for them!
Hope this helps :)
