understanding radioactive decay and half-life is crucial for explaining the heat generated by radioactive isotopes within Earth’s interior. These Crosscutting Concepts and Science and Engineering ...

A few years later, in 1907, he reasoned that since he knew the rate at which uranium breaks down (its half-life), he could use ... ore -- and by extension, the earth's crust -- had existed.

The discovery of radioactivity allowed scientists to develop new methods of determining Earth's age ... understand the mechanism of radioactive half-life and how it helps determine age by ...