Although `Cr^(3+)` and `Co^(2+)` ions have same number of unpaired electrons but the magnetic moment of `Cr^(3+)` is 3.87 B.M. and that of `Co^(2+)` is 4.87 B.M. Why ?

Explanation

To understand why the magnetic moments of `Cr^(3+)` and `Co^(2+)` ions differ despite having the same number of unpaired electrons, we can follow these steps:

### Step 1: Determine the electronic configurations
- **Chromium (Cr)** has an atomic number of 24. The electronic configuration of neutral chromium is `[Ar] 3d^5 4s^1`. When it loses three electrons to form `Cr^(3+)`, the configuration becomes `[Ar] 3d^3`.
- **Cobalt (Co)** has an atomic number of 27. The electronic configuration of neutral cobalt is `[Ar] 3d^7 4s^2`. When it loses two electrons to form `Co^(2+)`, the configuration becomes `[Ar] 3d^7`.

### Step 2: Count the number of unpaired electrons
- In `Cr^(3+)` with the configuration `[Ar] 3d^3`, there are 3 unpaired electrons (one in each of the three 3d orbitals).
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