History and Production
Named after Dmitri Mendeleev (1834-1907), who devised the periodic table of the elements. It was first identified by A. Ghiorso, B.H. Harvey, G.R. Choppin. S.G. Thompson and G.T. Seaborg in 1955, from bomardment of 253Es with helium ions. The isotope produced, 256Md, has a half-life of 78 minutes.
Only atomic quantities of the element has been produced. 258Md has the longest half-life of 52 days. It is possible to generate sufficient amount of this
isotope to study the chemical properties of mendelevium in solution.
Its physical data is not known since no sizable quantity has ever been produced.
Interatomic distance: -
Melting point: 827°C (est.)
Boiling point: n/a
Thermal conductivity/Wm-1K-1: 10 est. (27°C)
Standard Thermodynamic Data (atomic gas)
Enthalpy of formation: -
Gibbs free energy of formation: -
Heat capacity: -
Electronic configuration: Electronic configuration: [Rn] 5f13 7s2
Term symbol: 2F7/2
Electron affinity: - Electronegativity (Pauline): -
Ionization energy (first, second, third): 634.874, -, - kJ/mol