Question

The +3 oxidation state of lanthanum(z=57),gadilinium(z=64)and lutecium(z=71) is especially stable , why?

Answer 1

The +3 oxidation state of lanthanum(z=57),gadilinium(z=64)and lutecium(z=71) is especially stable. This is because they have empty, half filled and completely filled 4f sub- shell respectively.