The Element Fermium
[Click for Isotope Data]
Atomic Number: 100
Atomic Weight: 257
Melting Point: 1800 K (1527°C or 2781°F)
Boiling Point: Unknown
Phase at Room Temperature: Solid
Element Classification: Metal
Period Number: 7 Group Number: none Group Name: Actinide
Radioactive and Artificially Produced
What's in a name? Named after the scientist Enrico Fermi.
Say what? Fermium is pronounced as FER-mee-em.
History and Uses:
Fermium was discovered by a team of scientists led by Albert Ghiorso in 1952 while studying the radioactive debris produced by the detonation of the first hydrogen bomb. The isotope they discovered, fermium-255, has a half-life of about 20 hours and was produced by combining 17 neutrons with uranium-238, which then underwent eight beta decays. Today, fermium is produced though a lengthy chain of nuclear reactions that involves bombarding each isotope in the chain with neutrons and then allowing the resulting isotope to undergo beta decay.
Fermium's most stable isotope, fermium-257, has a half-life of about 100.5 days. It decays into californium-253 through alpha decay or decays through spontaneous fission.
Due to the small amounts produced and its short half-life, there are currently no uses for fermium outside of basic scientific research.
Estimated Crustal Abundance: Not Applicable
Estimated Oceanic Abundance: Not Applicable
Number of Stable Isotopes: 0 (View all isotope data)
Ionization Energy: 6.50 eV
Oxidation States: +3
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f12