Compare the general characteristics of the first series of the transition metals with those of the second and third series metals in the respective vertical columns. Give special emphasis on the following points :
electronic configurations

Explanation

Electronic configuration : The elements of first transition series involve progressive filling of 3d - orbitals while those of second and third transition series involve filling of 4d and 5d - orbitals, respectively. The elements in the same verical column generally have similar electronic configurations, although there are anomalies in groups 5, 6, 8, 9 and 10.