Standard State: presumably a solid at 298 K
Color: unknown, but probably metallic and silvery white or
Gray in appearance
Mendelevium is the ninth transuranium element of the actinide series to be discovered.
Ghiorso, Harvey, Choppin, Thompson, and Seaborg first identified it early in
1955. Experiments seem to show that the elements possesses a moderately stable dipositive
(II) oxidation state in addition to the tripositive (III) oxidation state, which is
characteristic of actinide elements.