Francium

Francium, the heaviest alkali metal, is very short-lived due to its intense radioactivity. Among its 30 known isotopes, Fr-223 has the longest lifespan with a half-life of 22 minutes. Fr-223, the daughter nuclei of Ac-227, is the only naturally occurring francium isotope. Although small amounts are found in uranium ores, the Fr-223 isotope is usually made from radium in nuclear reactors.

Currently, francium has no applications as a result of its relatively rapid disintegration. However, studies to develop uses for this element are being performed in nuclear research laboratories. As francium belongs to the alkali metals group, its properties are believed to be similar to those of cesium, the element used in the atomic clock at the National Research Council Canada (NRC).

Additional Information

Learn more about relevant NRC research:

• NRC-Institute for National Measurement Standards: Time Standards - Research Projects (NRC-INMS)