Nuclear Decay
Thankfully, not all isotopes are radioactive. Many are stable and last practically forever. There are a few general rules to predict whether an isotope is stable or radioactive:
- Small Nuclei - Atoms which contain up to 20 protons (up to Calcium) are usually stable.
- Large Nuclei - Larger nuclei tend to be radioactive. All nuclei with more than 84 protons (Polonium and up) are radioactive. For example, all isotopes of Uranium are radioactive.
- Atoms with more neutrons than protons - There are radioactive nuclei that have less than 84 protons. These nuclei have more neutrons than protons. For example, Carbon-12 (6 protons and 6 neutrons) is stable, while Carbon-14 (6 protons and 7 neutrons) is radioactive.
Now let's look at the types of nuclear reactions.
