francium

[ fran-see-uhm ]

noun

, Chemistry.

1. a radioactive element of the alkali metal group. : Fr; : 87.

francium

/ ˈfrænsɪəm /

noun

1. 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, ²²³Fr: 22 minutes; valency: 1; melting pt: 27°C; boiling pt: 677°C

francium

/ frăn′sē-əm /

1. 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.
2. See Periodic Table

Word History and Origins

Origin of francium¹

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

Word History and Origins

Origin of francium¹

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

Example Sentences

The last of the original 92 elements to be discovered was element 87, francium.

From Project Gutenberg