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100Fm257 u

Fermium

actinide
Atomic Number
100
Atomic Mass
257 u
Period
7
Group
3

Quick Facts

PropertyValue
SymbolFm
Atomic Number100
Atomic Mass[257] u
CategoryActinide
Period7
Group3
Blockf
Electron Configuration[Rn] 5f¹² 7s²

History and Discovery

Discovered by: Albert Ghiorso and colleagues Year of Discovery: 1952 Location: Debris from Ivy Mike hydrogen bomb test

Etymology

Named after Enrico Fermi, nuclear physics pioneer.

Interesting Facts

  1. Discovered alongside einsteinium in H-bomb debris
  2. Named after Enrico Fermi
  3. Last element that can be produced in macroscopic quantities
  4. Cannot be synthesized in reactors—only in explosions
  5. Heaviest element that can be made by neutron capture