a radioactive chemical element, an alkali metal, existing in minute amounts in nature as a decay product of actinium: symbol, Fr; at. no. 87
Origin of franciumModern Latin from France + -ium
An extremely unstable radioactive element of the alkali metals, produced by alpha decay of actinium or artificially from thorium, having over 40 isotopes and isomers, the most stable of which is Fr-223 with a half-life of 22 minutes. Atomic number 87; melting point 27°C; boiling point 677°C; valence 1. See Periodic Table.
Origin of franciumAfter France
- A metallic chemical element (symbol Fr) with an atomic number of 87.