Which of the following order of IP is incorrect

Options

A. `Na^(+)gtMg^(+)`
B. `Mg^(+2)gtMg^(+)`
C. `HegtLi^(+)`
D. `BegtB`

Answer

To determine which order of ionization potential (IP) is incorrect, we will analyze each option step by step.

### Step 1: Analyze the first option - Na⁺ > Mg²⁺
- **Electronic Configuration**:
- Na⁺: After losing one electron, the electronic configuration is 1s² 2s² 2p⁶ (Neon configuration).
- Mg²⁺: After losing two electrons, the electronic configuration is also 1s² 2s² 2p⁶ (Neon configuration).
- **Conclusion**: Both ions have the same electronic configuration (noble gas configuration). Therefore, the ionization potential of Na⁺ is equal to that of Mg²⁺, making this option incorrect.

### Step 2: Analyze the second option - Mg²⁺ > Mg⁺
- **Electronic Configuration**:
- Mg²⁺: 1s² 2s² 2p⁶ (Neon configuration).
- Mg⁺: After losing one electron, the electronic configuration is 1s² 2s² 2p⁶ 3s¹.
- **Conclusion**: Mg²⁺ has a completely filled outer shell (noble gas configuration), while Mg⁺ has one electron in the 3s orbital. Therefore, it requires more energy to remove an electron from Mg⁺ than from Mg²⁺. This order is correct.

### Step 3: Analyze the third option - He > Li⁺
- **Electronic Configuration**:
- He: 1s².
- Li⁺: After losing one electron, the electronic configuration is also 1s².
- **Conclusion**: Both He and Li⁺ have the same electronic configuration (1s²). Therefore, their ionization potentials should be equal, making this option incorrect.

### Step 4: Analyze the fourth option - Be > B
- **Electronic Configuration**:
- Be: 1s² 2s².
- B: 1s² 2s² 2p¹.
- **Conclusion**: Beryllium has a completely filled 2s orbital, while boron has an incomplete 2p orbital. Therefore, it is harder to remove an electron from Be than from B, making this order correct.

### Final Conclusion:
The incorrect order of ionization potential is **He > Li⁺**.