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fermium Syllabification: fer·mi·um
Pronunciation: /ˈfermēəm/

Definition of fermium in English:


The chemical element of atomic number 100, a radioactive metal of the actinide series. Fermium does not occur naturally and was discovered in 1953 in the debris of the first hydrogen bomb explosion. (Symbol: Fm)
Example sentences
  • Scientists have for the first time literally shed light on properties of the radioactive element fermium - a metal discovered some 50 years ago.
  • All isotopes of fermium are radioactive, with fermium-257 having the longest half life, 20.1 hours.
  • The transfermium elements are those elements with atomic numbers greater than 100, the atomic number for fermium.


1950s: from the name of E. Fermi (see Fermi, Enrico) + -ium.

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