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francium Syllabification: fran·ci·um
Pronunciation: /ˈfran(t)sēəm/

Definition of francium in English:


The chemical element of atomic number 87, a radioactive member of the alkali metal group. Francium occurs naturally as a decay product in uranium and thorium ores. (Symbol: Fr)
Example sentences
  • Along the way, these disintegration series produce radioactive isotopes of protactinium, thorium, actinium, radium, francium, radon, astatine, polonium, bismuth, lead, thallium and mercury.
  • Along the road to bismuth, a number of extremely high energy or otherwise dangerous alpha emitters will be present in the sample in small quantities: radium, actinium, thorium, francium, pollonium and radioactive lead, among others.
  • These elements - lithium, sodium, potassium, rubidium, cesium and francium - all react with water to give solutions that change the color of a vegetable dye from red to blue.


1940s: from France (the discoverer's native country) + -ium.

Definition of francium in:
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