Summary:
- Radioactive decay is the breakdown of unstable elements into stable elements.
- Atoms of an element with different numbers of neutrons are called isotopes.
- Carbon dioxide forms in the atmosphere from carbon-14 and oxygen.
- Carbon-14 has a half-life of 5,730 years.
- The rate of decay of a radioactive substance is constant over time.
- The decay rate of an unstable isotope to a stable element occurs at a constant rate.
- The half- life is the time it takes for half of a given amount of an isotopes to decay.