The energy required to pull the most loosely bound electrons from an atom is known as ionization potential. It is expressed in electron volts. The value of ionization potential depends on three factors :(i) the charge on the nucleus (ii) the atomic radius and (iii) the screening effect of inner electron shells.
Ionization potential of Na would be numerically the same as

Options

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

Answer

To solve the question regarding the ionization potential of sodium (Na), we need to understand the relationship between ionization energy and electron affinity, as well as how these concepts apply to sodium and its ions. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand Ionization Potential
- **Definition**: Ionization potential (or ionization energy) is the energy required to remove the most loosely bound electron from an atom in its gaseous state.
- **Expression**: It is expressed in electron volts (eV).

### Step 2: Factors Affecting Ionization Potential
- The ionization potential depends on:
1. **Charge on the nucleus**: Higher positive charge increases ionization potential.
2. **Atomic radius**: A smaller atomic radius generally leads to higher ionization potential due to increased attraction between the nucleus and electrons.
3. **Screening effect**: Inner electron shells can shield the outer electrons from the nucleus, reducing ionization potential.

### Step 3: Ionization of Sodium
- When we remove one electron from sodium (Na), it becomes Na⁺:
\[ \text{Na} \rightarrow \text{Na}^+ + e^- \]
- The energy required for this process is the ionization potential of sodium.

### Step 4: Relationship with Electron Gain Enthalpy
- When we add an electron to Na⁺ to form Na, the energy released is known as the electron gain enthalpy:
\[ \text{Na}^+ + e^- \rightarrow \text{Na} \]
- According to Hess's law, the energy required to remove an electron from Na is numerically equal to the energy released when an electron is added to Na⁺.

### Step 5: Identifying the Correct Answer
- The question asks for the value of ionization potential of Na, which would be numerically the same as the electron affinity of Na⁺.
- **Options Analysis**:
- **Electron affinity of Na⁺**: Correct, as it relates to the addition of an electron to Na⁺.
- **Electronegativity of sodium**: Incorrect, as electronegativity is a different concept.
- **Electron affinity of sodium**: Incorrect, as it does not relate to Na⁺.
- **Ionization potential of magnesium**: Incorrect, as there is no direct correlation.

### Conclusion
The ionization potential of sodium (Na) would be numerically the same as the electron affinity of Na⁺.

### Final Answer
**The ionization potential of Na would be numerically the same as the electron affinity of Na⁺.**

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