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 among the given options, we need to analyze the electron configurations and the stability of the ions involved. Here’s a step-by-step solution:

### Step 1: Understand Ionization Potential (IP)
Ionization potential is the energy required to remove an electron from an atom or ion. Generally, the more stable the electron configuration (like noble gas configurations), the higher the ionization potential.

### Step 2: Analyze the Given Ions
1. **Na⁺ (Sodium ion)**: Sodium has 11 electrons, and when it loses one electron to form Na⁺, it has 10 electrons, achieving a noble gas configuration (Neon).
2. **Mg²⁺ (Magnesium ion)**: Magnesium has 12 electrons, and when it loses two electrons to form Mg²⁺, it also has 10 electrons, achieving a noble gas configuration (Neon).
3. **Li⁺ (Lithium ion)**: Lithium has 3 electrons, and when it loses one electron to form Li⁺, it has 2 electrons, achieving a noble gas configuration (Helium).
4. **Be²⁺ (Beryllium ion)**: Beryllium has 4 electrons, and when it loses two electrons to form Be²⁺, it has 2 electrons, achieving a noble gas configuration (Helium).
5. **B (Boron)**: Boron has 5 electrons, and its configuration is 1s² 2s² 2p¹.

### Step 3: Compare Ionization Potentials
- **Na⁺ vs. Mg²⁺**: Both have the same electron configuration (10 electrons), but Na⁺ has a lower nuclear charge (11 protons) compared to Mg²⁺ (12 protons). Thus, Na⁺ will have a lower IP than Mg²⁺.
- **Li⁺ vs. He**: Li⁺ has 3 protons and 2 electrons, while He has 2 protons and 2 electrons. The higher nuclear charge in Li⁺ results in a higher IP compared to He.
- **Be²⁺ vs. B**: Be²⁺ has 4 protons and 2 electrons, while B has 5 protons and 5 electrons. Be²⁺ is more stable due to its complete shell, leading to a higher IP than B.

### Step 4: Identify the Incorrect Order
From the analysis, we can conclude:
- The order of IP for Li⁺ is higher than for He, which is correct.
- The order of IP for Be²⁺ is higher than for B, which is also correct.
- However, the order of IP for Na⁺ and Mg²⁺ must be checked against the given options to see if any incorrect order is stated.

### Conclusion
The incorrect order of ionization potential is likely to be the one that suggests Li⁺ has a lower IP than another ion with a similar electron configuration, or that Na⁺ has a higher IP than Mg²⁺. Based on the analysis, the answer is **Option 3**.