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
a. The first series transition metals have lower atomic numbers and smaller atomic radii compared to the second and third series metals.
b. The second and third series transition metals generally exhibit higher melting and boiling points than the first series metals.
c. The first series transition metals tend to form less stable oxidation states compared to the second and third series metals.
d. The second and third series transition metals have more complex electron configurations compared to the first series metals.