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francium
[ fran-see-uhm ]
noun
- a radioactive element of the alkali metal group. : Fr; : 87.
francium
/ ˈfrænsɪəm /
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, 223Fr: 22 minutes; valency: 1; melting pt: 27°C; boiling pt: 677°C
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
Word History and Origins
Word History and Origins
Origin of francium1
Example Sentences
Lithium, sodium and potassium, which nicely align in the table’s first vertical column — Group One, the alkali metals, with rubidium, cesium, and francium — all have one electron in their outer electron shell.
The team’s proposed name follows suit with other atomic elements like polonium named after Poland, francium after France, and americium after the United States.
It will also not be the only element to be named after a country, having been proceeded by polonium and francium after the places they were discovered.
It is evident in entries like francium, germanium, scandium, polonium, europium, californium, berkelium and americium.
The last of the original 92 elements to be discovered was element 87, francium.
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