(I) Mn+2 in weak field ligand has configuration d5 so no. of unpaired e− =5 (II) Ni+2 in strong field ligand in octahydral field has configuration eg6t2g2 so no. of unpaired e− is 2 (III) CN− is strong ligand and it has configuration eg3 so no.of unpaired e− is equal to 3. (IV) Sc3+ has 'o' unpaired e−