Name Fermium
Symbol Fm
Atomic Number 100
Atomic Mass 257 atomic mass units
Number of Protons 100
Number of Neutrons 157
Number of Electrons 100
Melting Point 1527.0 C
Boiling Point Unknown
Density Unknown
Normal Phase Synthetic
Family Rare Earth Metals
Period 7
Cost Unavailable



Origin of Name After Enrico Fermi
Date and Place of Discovery In 1952 from the debris of the thermonuclear explosion at Eniwetok in the Pacific during Operation Ivy
The work was supervised by the University of California Radiation Laboratory, Argonne National Laboratory, and Los Alamos Scientific Laboratory.
Discovered by Gregory R. Choppin, Albert Ghiorso, B. G. Harvey and Stanley G. Thompson
Common Compounds
Interesting facts
  • It is very radioactive.
  • It is created by bombarding plutonium with neutrons.
  • Only a very little amount of it has been produced so little is known about its chemical characteristics.
  • Its discovery was kept secret until 1955 due to the Cold War.
Common Uses There are no known uses.


Photo Courtesy of Lenn Tech
Chemical Elements
Jefferson Lab
Web Elements

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