Francium - Fr
Chemical properties of francium
| Atomic number | 87 |
|---|---|
| Representative mass number | 223 (Fr-223; radioactive) |
| Electron configuration | [Rn] 7s1 |
| Melting point | Not established reliably |
| Boiling point | Not established reliably |
| Density | Not established reliably |
Francium (Fr) is a radioactive alkali metal with atomic number 87. It has no stable isotopes; the longest-lived known isotope is francium-223, with a half-life of about 22 minutes. Because only minute numbers of atoms are present at a time, bulk physical properties such as density and melting point have not been measured reliably. Values sometimes quoted for these properties are estimates.
Uses and occurrence
Francium occurs only in trace amounts in the decay chains of heavier radioactive elements and is produced for scientific research. Its short half-life and extreme scarcity leave no practical industrial or water-treatment application.
Health and environmental context
Francium decays rapidly and does not accumulate as a persistent environmental contaminant. Radiation protection is relevant to controlled research handling; this page is not a guide to managing radioactive materials.
Back to the periodic table of elements.
Sources and further reading
Francium page last reviewed: by Lenntech.