(i) Name the element of 3d transition series which shows maximum number of oxidation states. Why does it show so ?
(ii) Out of `Cr_(3+) and Mn^(3+)` which is a stronger oxidising agent and why?
(iii) Why is zinc not regarded as a transition element ? (At. no. Zn=3)

Explanation

(i) Mn
(ii) `Mn^(3+)`
(iii) Due to the presence of large number of unpaired electrons in their atoms.