Discovered | Name | Characteristics

Mendelevium is a member of the actinide series, which stretches from actinium (Ac) to lawrencium (Lr). Mendelevium is a synthetic element; none occurs naturally on earth.

As with so many of the other transuranium elements - the elements beyond uranium - Md was first synthesized by Seaborg and his co-workers at the University of California at Berkeley (A. Ghiorso, B.G. Harvey, G.R. Choppin, S.G. Thompson). It can be produced by bombarding einsteinium with alpha particles.

255Es + 4He 258Md + 1n

The element is named for Dmitri Mendeléev, the person who first developed the notion of chemical periodicity.

At least 11 isotopes of Md are known. The most stable isotope is 258Md, which has a half-life of about 56 days.

Little is known about its chemistry. However, it is thought that its compounds have oxidation numbers of +2 and +3, with +3 being the more stable.