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 :
oxidation states

Explanation

Oxidation states : Elements lying in the middle of each transition series show maximum number of oxidation states, while those lying near the two ends show only few oxidation states. For the elements of first transition series, + 2 and + 3 oxidation states are very common and these elements form stable complexes such as `[CrCl_(6)]^(3-), [Co(NH_(3))_(6)]^(3+)` etc., in these oxidation states. The elements of second and third series, however, form many stable compounds in higher oxidation states. Examples of such compounds are `RuO_(4), OsO_(4), ReF_(7), WCl_(6), PtF_(6)`, etc. 1st row transition elements do not show + 8 oxidation state.