`Pt^(4+)` is less / more stable than `Ni^(4+)` .

Explanation

To determine whether \( \text{Pt}^{4+} \) is more or less stable than \( \text{Ni}^{4+} \), we need to analyze their electronic configurations and the stability associated with their oxidation states.

### Step 1: Determine the electronic configurations
- **Platinum (Pt)** has an atomic number of 78. Its ground state electronic configuration is:
\[ \text{[Xe]} 4f^{14} 5d^9 6s^1 \]
- **Nickel (Ni)** has an atomic number of 28. Its ground state electronic configuration is:
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