Chemistry - Complete d-block Question with Solution | TestHub

Question Explanation: Identify the ion with the highest magnetic moment among the given options.

Concept: Magnetic moment depends on unpaired electrons.

Solution: The spin-only magnetic moment ($\mu$) is proportional to the number of unpaired electrons ($n$), where $\mu =\sqrt{n(n+2)}$ BM. Maximum magnetic moment means the maximum number of unpaired electrons.

We determine the electronic configuration and number of unpaired electrons ($n$) for each ion:

- Zn²⁺(z=30) : [Ar]3d¹⁰, $n=0$ (Diamagnetic).

- Ca²⁺(z=20) : [Ar], $n=0$ (Diamagnetic).

- Mn²⁺(z=25) : [Ar]3d⁵, $n=5$ (Paramagnetic, maximum unpaired electrons).

- Mg²⁺(z=12) : [Ne], $n=0$ (Diamagnetic).

Manganese(II) ion (Mn²⁺) has the highest number of unpaired electrons (5) and thus the maximum magnetic moment.

Final Answer: option (c)