The Element Mendelevium
[Click for Isotope Data]
Atomic Number: 101
Atomic Weight: 258
Melting Point: 1100 K (827°C or 1521°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 Russian chemist Dmitri Mendeleyev.
Say what? Mendelevium is pronounced as men-deh-LEE-vee-em.
History and Uses:
Mendelevium was first produced by Stanley G. Thompson, Glenn T. Seaborg, Bernard G. Harvey, Gregory R. Choppin and Albert Ghiorso working at the University of California, Berkeley, in 1955. They bombarded atoms of einsteinium-253 with helium ions using a device known as a cyclotron. This produced atoms of mendelevium-256, an isotope with a half-life of about 77 minutes, and a free neutron.
Mendelevium's most stable isotope, mendelevium-258, has a half-life of about 51.5 days. It decays into einsteinium-254 through alpha decay or decays through spontaneous fission.
Since only small amounts of mendelevium have ever been produced, it currently has no uses 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: 6.58 eV
Oxidation States: +3, +2
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f13