Overview

In 1934, the French chemists Frédéric and Irène Joliot-Curie produced radioactivity artificially. In other words, they produced radioactivity in elements that are not naturally radioactive. One important use of artificial radioactivity is in the diagnosis and treatment of disease. In addition, the Joliot-Curies' breakthrough helped lead to the discovery of nuclear fission.

Background

All atoms of an element have the same number of protons. The number of neutrons in the atoms of an element, however, may vary. Atoms of the same element that have different numbers of neutrons are called isotopes. For example, carbon-12 and carbon-14 are isotopes of carbon. (Carbon-12 has six protons and six neutrons, and carbon-14 has six protons and eight neutrons.)

Radioactivity is a property of certain unstable isotopes. The nuclei of radioactive isotopes emit matter and/or energy. This emission is called...