| 1 |
Establishing exactly how many years an object, such as a rock layer or fossil, has existed is called [ _______ ]. |
| 2 |
[ _______ ] are atoms of the same element that have the same number of protons but different numbers of neutrons. |
| 3 |
Most isotopes are [ _______ ] meaning they stay in their original form. |
| 4 |
Isotopes that are unstable are called [ _______ ]. |
| 5 |
Explain how an unstable isotope changes. |
| 6 |
Radioactive isotopes tend to break down into stable isotopes of different elements. This process is called [ _______ ]. |
| 7 |
The Uranium-Lead Method proves it takes [ _______ ] years for one half life to occur. |
| 8 |
What is a half-life? |
| 9 |
If one half-life takes 10,000 years, how old is a sample with 75% daughter material. |
| 10 |
If one half-life takes 100,000 years, how old is a sample with 87.5% daughter material. |
