Correct order of second ionization energy among the following is:

Options

A. `Li^+gt C^+gt B^+gt Be^+`
B. `C^+ gt B^+ gt Be^+ gt Li^+`
C. `B^+gt Be^+gt C^+gt Li^+`
D. `Li^+ gt B^+ gt C^+ gt Be^+ `

Answer

To determine the correct order of second ionization energy among the given elements (Li, B, C, and Be), we will analyze the electronic configurations and the stability of the resulting ions after the removal of electrons.

### Step-by-Step Solution:

1. **Identify the Electronic Configurations:**
- Lithium (Li): Atomic number 3 → Electronic configuration: 1s² 2s¹
- Beryllium (Be): Atomic number 4 → Electronic configuration: 1s² 2s²
- Boron (B): Atomic number 5 → Electronic configuration: 1s² 2s² 2p¹
- Carbon (C): Atomic number 6 → Electronic configuration: 1s² 2s² 2p²

2. **First Ionization:**
- When the first electron is removed:
- Li → Li⁺: 1s² (removal of 2s electron)
- Be → Be⁺: 1s² 2s¹ (removal of 2s electron)
- B → B⁺: 1s² 2s² 2p⁰ (removal of 2p electron)
- C → C⁺: 1s² 2s² 2p¹ (removal of 2p electron)

3. **Second Ionization:**
- Now, we consider the second ionization energy (removal of another electron):
- Li⁺ → Li²⁺: 1s⁰ (removal of 1s electron)
- Be⁺ → Be²⁺: 1s² (removal of 2s electron)
- B⁺ → B²⁺: 1s² 2s² (removal of 2s electron)
- C⁺ → C²⁺: 1s² 2s² 2p⁰ (removal of 2p electron)

4. **Stability of Ions:**
- **Li²⁺**: Removing an electron from a filled 1s orbital requires a large amount of energy due to the strong attraction between the nucleus and the remaining electrons.
- **Be²⁺**: After the first ionization, Be⁺ has a stable noble gas configuration (1s²), so removing another electron (from 2s) requires significant energy, but less than Li²⁺.
- **B²⁺**: After the first ionization, B⁺ has a filled 2s² configuration, making it relatively stable. Removing an electron from 2s requires less energy than removing from 1s or a filled shell.
- **C²⁺**: After the first ionization, C⁺ has a filled 2s² and one 2p electron. Removing a 2p electron is easier than removing from a filled 2s or 1s orbital.

5. **Order of Second Ionization Energies:**
- Based on the above analysis, the order of second ionization energies from highest to lowest is:
- Li > B > C > Be

### Final Answer:
The correct order of second ionization energy is: **Li > B > C > Be**