Question

Decide giving reason which one of the following pairs has the property indicated:

Co²⁺ or Ni²⁺ has lower magnetic moment.

Answer 1

1. The magnetic moment depends on the number of unpaired electrons in the ion.
2. Co²⁺ has 3 unpaired electrons (electronic configuration: [Ar] 3d⁷), while Ni²⁺ has two unpaired electrons (configuration: [Ar] 3d⁸).
3. More unpaired electrons mean a higher magnetic moment; hence, Co²⁺ has a higher magnetic moment than Ni²⁺.
4. Therefore, Ni²⁺ has a lower magnetic moment than Co²⁺ because it has fewer unpaired electrons in its d-orbitals.