D and F Block 1

Originally the name transition metals was derived from the fact that their chemical properties were transitional between those of s and p-block elements. A transition element may be defined as the element whose atom in ground state or in one of common oxidation states, has partly filled d-sub shell i.e. having electrons from 1 to 9. Zinc, cadmium and mercury of group 12 have full d 10 configuration in their ground state as well as in their common oxidation states and hence, are not regarded as transition metals.