francium

[fran-see-uh m]

noun Chemistry.

a radioactive element of the alkali metal group. Symbol: Fr; atomic number: 87.

Origin of francium

1945–50; after France where first identified; see -ium

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for francium

Historical Examples of francium

The last of the original 92 elements to be discovered was element 87, francium.
A Brief History of Element Discovery, Synthesis, and Analysis
Glen W. Watson

British Dictionary definitions for francium

francium

noun

an unstable radioactive element of the alkali-metal group, occurring in minute amounts in uranium ores. Symbol: Fr; atomic no: 87; half-life of most stable isotope, 223 Fr: 22 minutes; valency: 1; melting pt: 27°C; boiling pt: 677°C

Word Origin for francium

C20: from New Latin, from France + -ium; so-called because first found in France

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

francium in Medicine

francium

[frăn′sē-əm]

n. Symbol Fr

An extremely unstable radioactive element of the alkali metals, having approximately 19 isotopes, the most stable of which is Fr 223 with a half-life of 21 minutes. Atomic number 87.

francium in Science

francium

[frăn′sē-əm]

An extremely unstable, radioactive element of the alkali group. It is the heaviest metal of the group. Francium occurs in nature, but less than 28.35 g (1 oz) is present in the Earth's crust at any time. It has approximately 19 isotopes, the most stable of which is Fr 223 with a half-life of 21 minutes. Atomic number 87; valence 1. See Periodic Table.