Which out of `Cu^(2+), Fe^(2+) and Cr^(3+)` has highest paramagnetism and why ?

Explanation

To determine which ion among Cu²⁺, Fe²⁺, and Cr³⁺ has the highest paramagnetism, we need to analyze the electronic configurations of each ion and count the number of unpaired electrons. The more unpaired electrons an ion has, the higher its paramagnetism.

### Step 1: Determine the electronic configuration of each ion.

1. **Copper (Cu²⁺)**:
- Atomic number of Cu = 29
- Ground state configuration: [Ar] 4s² 3d⁹
- For Cu²⁺, we remove 2 electrons:
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