by Glenn T. Seaborg, Albert Ghiorso, Bernard Harvey, Gregory Choppin, Stanley G. Thompson at 1955 in USA. Origin of name
: named after Dimitri "Mendeleev
", the Russian chemist who contributed so much to the development of the periodic table.
Mendelevium, the ninth transuranium element of the actinide series to be discovered, was first identified by Seaborg and others in 1955 as a product of the bombardment of the einsteinium isotope 253Es with helium ions. The isotope produced was 256Md, which has a half-life of about 11/4 hours.