Which one of the following statements is correct in relation to the ionization enthalpy ?

Options

A. Electron`-` electron interaction in the outer orbitals of the elements increases the ionization enthalpy.
B. Removal of electron from orbitals bearing higher `'n'` value is easier than from orbitals having lower `'n'` value.
C. The ionization enthalpies of iso`-` electronic species, `F^(-)`, Ne and `Na^(+)` are same because their size and electron configuration are same.
D. End of valence electrons is indicated by a small jump in ionization enthalpy.

Explanation

To determine which statement is correct regarding ionization enthalpy, we will analyze each of the four statements provided.

### Step-by-Step Solution:

1. **Understanding Ionization Enthalpy**:
- Ionization enthalpy (or ionization energy) is defined as the energy required to remove an electron from the outermost shell of a neutral atom.

2. **Analyzing Statement 1**:
- **Statement**: "Electron-electron interaction in the outer orbitals of the elements increases the ionization enthalpy."
- **Analysis**: This statement is incorrect. Electron-electron repulsion in the outer orbitals actually decreases the ionization enthalpy because it makes it easier to remove an electron due to increased repulsion among electrons.

3. **Analyzing Statement 2**:
- **Statement**: "The removal of an electron from the orbital bearing a higher n value is easier than from orbitals having a lower n value."
- **Analysis**: This statement is correct. As the principal quantum number (n) increases, the distance of the outermost electron from the nucleus increases, leading to a weaker attraction between the nucleus and the outermost electron. Therefore, it is easier to remove an electron from orbitals with a higher n value.

4. **Analyzing Statement 3**:
- **Statement**: "The ionization enthalpy of isoelectronic species (fluoride ion, neon, and sodium metal) are the same because their size and electronic configuration are the same."
- **Analysis**: This statement is false. Although these species are isoelectronic (having the same number of electrons), their ionization enthalpies differ due to their different nuclear charges and the nature of their electronic configurations (Neon being a noble gas, Sodium being a metal, and Fluoride being an anion).

5. **Analyzing Statement 4**:
- **Statement**: "End of valence electron is indicated by a small jump in ionization enthalpy."
- **Analysis**: This statement is also false. A significant jump in ionization enthalpy indicates the removal of an electron from a new inner shell, not a small jump.

6. **Conclusion**:
- The only correct statement regarding ionization enthalpy is **Statement 2**.

### Final Answer:
The correct statement in relation to ionization enthalpy is: **The removal of an electron from the orbital bearing a higher n value is easier than from orbitals having lower n value.**

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