Question #09d7f

1 Answer

Copper has two oxidation states because it can lose either one or two valence electrons.

Explanation:

Copper has a valence electron configuration of #"4s"^1 "3d"^10#.

The #"4s"# and #"3d"# levels are very close in energy, so copper can lose one or two electrons.

In copper(II), copper loses two electrons, leaving #"3d"^9#.

In copper(I), copper loses its #"4s"# electron. This gives a valence configuration of #"3d"^10#.

The #"3d"^10# configuration is somewhat stable as it is a filled subshell.