Mike's+Page

Radioactive Disintegration Series

Any element with an atomic number larger than bismuth has one or more isotopes that are radioactive. Elements like potassium and rubidium and a few others with low atomic numbers have naturally occurring isotopes which are radioactive.

The heavier elements experience radioactive decays and belong to a radioactive family or series. There are four radioactive series which includes, the uranium series, the actinium series, the thorium series and the neptunium series. Each series is characterized by the first member of long half-life and a series of decay processes which lead to a stable end product. With the three natural series (Uranium series, Actinium series,Thorium series) the end products are isotopes of lead: Pb206 in the uranium series, Pb207 in the actinium series, and Pb208 in the thorium series.

When an atom emits an alpha-particle, the product is an isotope of an element two places to the left of the parent element in the Periodic Table. When a beta-particle is emitted, the product is an isotope of an element one place to the right of the parent in the Periodic Table.

The neptunium series, which was discovered during World War II, named after its member of longest half-life, and it was discovered through the production of its members by artificial means. The end product of the series is an isotope of bismuth, Bi209.

http://www.3rd1000.com/chptr5.htm