Which of the following is incorrect?

Options

A. `IE_(1)" of "Li lt IE_(1)" of "Be`
B. `IE_(1)" of "Be lt IE_(1)" of "B`
C. `IE_(1)" of "Li gt IE_(1)" of "Na`
D. `IE_(1)" of "He gt IE_(1)" of "Ne`

Answer

To determine which statement regarding ionization enthalpy is incorrect, we will analyze the ionization enthalpy of the given pairs of elements based on their electronic configurations and stability.

### Step 1: Understand Ionization Enthalpy
Ionization enthalpy (or ionization energy) is the minimum amount of energy required to remove an electron from the gaseous state of an atom. The key factors affecting ionization enthalpy are:
- The stability of the electron configuration (fully filled or half-filled configurations are more stable).
- The distance of the electron from the nucleus (electrons in outer shells are held less tightly than those in inner shells).

### Step 2: Analyze the Given Options
1. **Option A: Lithium (Li) and Beryllium (Be)**
- **Lithium (Li)**: Atomic number 3 → 1s² 2s¹
- **Beryllium (Be)**: Atomic number 4 → 1s² 2s²
- Beryllium has a fully filled 2s subshell, making it more stable than lithium's half-filled 2s subshell. Therefore, it requires more energy to remove an electron from beryllium than from lithium.
- **Conclusion**: This statement is correct.

2. **Option B: Beryllium (Be) and Boron (B)**
- **Beryllium (Be)**: 1s² 2s²
- **Boron (B)**: Atomic number 5 → 1s² 2s² 2p¹
- Beryllium has a fully filled 2s subshell, while boron has one electron in the 2p subshell, which is less stable. Therefore, it is easier to remove an electron from boron than from beryllium.
- **Conclusion**: This statement is incorrect (it should state that Be has higher ionization energy than B).

3. **Option C: Lithium (Li) and Sodium (Na)**
- **Lithium (Li)**: 1s² 2s¹
- **Sodium (Na)**: Atomic number 11 → 1s² 2s² 2p⁶ 3s¹
- Lithium has its outermost electron in the 2nd shell, while sodium has its outermost electron in the 3rd shell. The outer electron in sodium is held less tightly due to the increased distance from the nucleus.
- **Conclusion**: This statement is correct (Li has higher ionization energy than Na).

4. **Option D: Helium (He) and Neon (Ne)**
- **Helium (He)**: Atomic number 2 → 1s²
- **Neon (Ne)**: Atomic number 10 → 1s² 2s² 2p⁶
- Helium has its electrons in the first shell, while neon has its electrons in the second shell. The hold of the nucleus on the electrons in helium is stronger than that in neon due to the smaller size and greater effective nuclear charge.
- **Conclusion**: This statement is correct (He has higher ionization energy than Ne).

### Final Conclusion
The incorrect statement is **Option B** (Beryllium has a higher ionization energy than Boron).