Ionisation enthalpy of Na would be same as

Options

A. electron affinity of `Na^(+)`
B. electronegativity of `Na^(+)`
C. electron affinity of Na
D. ionization potential of Mg

Explanation

To determine which property has the same value as the ionization enthalpy of sodium (Na), we need to understand the definitions and relationships between ionization enthalpy, electron affinity, and other related concepts. Here’s a step-by-step solution:

### Step-by-Step Solution:

1. **Define Ionization Enthalpy**:
- Ionization enthalpy (ΔH_ie) is the energy required to remove an electron from a gaseous atom to form a cation. For sodium, this can be represented as:
\[ \text{Na(g)} \rightarrow \text{Na}^+(g) + e^- \]

2. **Define Electron Affinity**:
- Electron affinity (ΔH_ea) is the energy released when an atom gains an electron to form an anion. For sodium, this can be represented as:
\[ \text{Na}^+(g) + e^- \rightarrow \text{Na(g)} \]
- This process releases energy.

3. **Relationship Between Ionization Enthalpy and Electron Affinity**:
- The ionization enthalpy of sodium is numerically equal to the electron affinity of sodium ion (Na⁺) because the processes are essentially reverse of each other. The energy required to remove an electron from Na is equal to the energy released when Na⁺ gains an electron to become Na.

4. **Conclusion**:
- Therefore, the ionization enthalpy of sodium (Na) is the same as the electron affinity of sodium ion (Na⁺).

5. **Final Answer**:
- The ionization enthalpy of Na would be the same as the electron affinity of Na⁺.