AP EAPCET 25-Aug-2021 Shift 1 Paper

Fe(Z=26)=[Ar]4s23d6
(∴ Highest oxidation state of Fe is +3)
Mn(Z=25)=[Ar]4s23d5 (5 unpaired electrons in 3d-orbital and 2e−in 4s.)
Mn can show 6 oxidation states from MnO to MnO4−.
Cr(Z=24)=[Ar]4s13d5
(∴ Highest oxidation state of Cr is +3)
V(Z=23)=[Ar]3d34s2
( ∴ Highest oxidation state of V is +2)
Hence, greatest number of oxidation state is shown by Mn.