Page "Cadmium" Paragraph 0

Cadmium ( ) is a chemical element with the symbol Cd and atomic number 48.

This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury.

Like zinc, it prefers oxidation state + 2 in most of its compounds and like mercury it shows a low melting point compared to transition metals.

Cadmium and its congeners are not always considered transition metals, in that they do not have partly filled d or f electron shells in the elemental or common oxidation states.

The average concentration of cadmium in the Earth's crust is between 0. 1 and 0. 5 parts per million ( ppm ).

It was discovered in 1817 simultaneously by Stromeyer and Hermann, both in Germany, as an impurity in zinc carbonate.