Which of the following has the maximum number of ampaired electrons ?

Options

A. `Mg^(2+)`
B. `Ti^(3+)`
C. `V^(3+)`
D. `Fe^(2+)`

Explanation

To determine which of the given ions has the maximum number of unpaired electrons, we will analyze the electronic configurations of each ion step by step.

### Step 1: Identify the Atomic Numbers and Configurations
We need to identify the atomic numbers of the ions and write their electronic configurations.

1. **Magnesium (Mg²⁺)**:
- Atomic Number: 12
- Ground State Configuration: \(1s^2 2s^2 2p^6 3s^2\)
- Ionic Configuration (Mg²⁺): \(1s^2 2s^2 2p^6\)

2. **Titanium (Ti)**:
- Atomic Number: 22
- Ground State Configuration: \([Ar] 3d^2 4s^2\)
- Ionic Configuration (Ti³⁺): \([Ar] 3d^1 4s^0\)

3. **Vanadium (V)**:
- Atomic Number: 23
- Ground State Configuration: \([Ar] 3d^3 4s^2\)
- Ionic Configuration (V³⁺): \([Ar] 3d^2 4s^0\)

4. **Iron (Fe)**:
- Atomic Number: 26
- Ground State Configuration: \([Ar] 3d^6 4s^2\)
- Ionic Configuration (Fe²⁺): \([Ar] 3d^6 4s^0\)

### Step 2: Count the Unpaired Electrons
Now we will count the number of unpaired electrons for each ion.

1. **Magnesium (Mg²⁺)**:
- Configuration: \(1s^2 2s^2 2p^6\)
- Unpaired Electrons: 0 (all electrons are paired)

2. **Titanium (Ti³⁺)**:
- Configuration: \([Ar] 3d^1 4s^0\)
- Unpaired Electrons: 1 (1 unpaired electron in 3d)

3. **Vanadium (V³⁺)**:
- Configuration: \([Ar] 3d^2 4s^0\)
- Unpaired Electrons: 2 (2 unpaired electrons in 3d)

4. **Iron (Fe²⁺)**:
- Configuration: \([Ar] 3d^6 4s^0\)
- Unpaired Electrons: 4 (4 unpaired electrons in 3d)

### Step 3: Conclusion
After counting the unpaired electrons for each ion, we find:
- Mg²⁺: 0 unpaired electrons
- Ti³⁺: 1 unpaired electron
- V³⁺: 2 unpaired electrons
- Fe²⁺: 4 unpaired electrons

**Therefore, the ion with the maximum number of unpaired electrons is Fe²⁺ with 4 unpaired electrons.**

### Final Answer
The correct option is **D: Iron (Fe²⁺)**.