The electronic configurations of the given elements are as ‌25‌Mn=[Ar]3d54s2 (∴5 unpaired electrons) ‌24‌Cr=[Ar]3d54s1 (∴6 unpaired electrons) ‌28‌Ni=[Ar]3d84s2(∴2 unpaired electrons) ‌26‌Fe=[Ar]3d64s2 (∴4 unpaired electrons) Hence, ‌24‌Cr is having highest number of unpaired electrons i.e., 6 Magnetic moment =√6(6+2)=√48=6.92‌BM (Highest magnetic moment)