Out of Mn3+ and Cr3+, which is more paramagnetic and why ?
(Atomic nos. : Mn = 25, Cr = 24)
Mn3+ has four unpaired electrons (d4) in its valence shell whereas Cr3+ (d3) has three unpaired electrons. Thus, Mn3+ is more paramagnetic than Cr3+.
Mn+3 = [Ar] 4s0 3d4 (4 unpaired e-)
Cr+3 = [Ar] 4s0 3d3 (3 unpaired e-)
Mn+3 has more no. of unpaired e- than Cr+3