francium

n. (Fr) radioactive chemical element

Francium (IPA: ), formerly known as eka-caesium and actinium K, is a chemical element that has the symbol Fr and atomic number 87. It has the lowest known electronegativity and is the second rarest naturally occurring element (after Astatine). Francium is a highly radioactive metal that decays into astatine, radium, and radon. As an alkali metal, it has one valence electron.
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Noun
1. a radioactive element of the alkali-metal group discovered as a disintegration product of actinium
(synonym) Fr, atomic number 87
(hypernym) metallic element, metal

n. (also: Fr) francium, alkali metal element, radioactive chemical element

Atomic Mass : 223
Atomic Number : 87
Name Origins: Named after France
Year Discovered : 1939
Discovery Credits : Discovered by Marguerite Perey in Paris, France.
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