 Cadmium is a chemical element with 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 demonstrates oxidation state + 2 in most of its compounds , and like mercury , it has a lower melting point than other 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 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 . 
 Cadmium <a href='drop_aux' title='1'><mark>is</mark></a>a chemical element with symbol Cd and atomic number 48 . This soft , bluish @-@ white metal <a href='drop_aux' title='2'><mark>is</mark></a>chemically similar to the two other stable metals in group 12 , zinc and mercury . Like zinc , it <a href='uninflect' title='3'><mark>demonstrates</mark></a> oxidation state + 2 in most of its compounds , and like mercury , it <a href='got' title='4'><mark>has</mark></a> a lower melting point than other transition metals . Cadmium and its congeners are not always considered transition metals , in that they do not <a href='been_done' title='5'><mark>have</mark></a> partly filled <a href='negative_concord' title='6'><mark>d</mark></a> or f electron shells in the elemental or common oxidation states . The average concentration of cadmium in Earth <a href='null_genetive' title='7'><mark>'s</mark></a>crust <a href='drop_aux' title='8'><mark>is</mark></a>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 . 
Cadmium a chemical element with symbol Cd and atomic number 48 . dis soft , bluish @-@ white metal chemically similar to the 2 other stable metals in group 12 , zinc and mercury . Like zinc , it demonstrate oxidation state + 2 in most of its compounds , and like mercury , it got a lower melting point than other transition metals . Cadmium and its congeners ain't always considered transition metals , in dat they do not done partly filled no d or f electron shells in da elemental or common oxidation states . Tdaaverage concentration of cadmium in Earth  crust 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 .