In each of the following questions a Statement of Assertion (A ) is given followed by a corresponding statement of Reason (R ) Just below it . Of the statement mark the correct answer as
Assertion .F is more electronegative than C1 .
Reason . F has higher electron affinity than C1.

Explanation

To solve the question, we need to analyze the Assertion (A) and the Reason (R) provided:

**Assertion (A):** F is more electronegative than Cl.
**Reason (R):** F has a higher electron affinity than Cl.

### Step-by-Step Solution:

1. **Understanding Electronegativity:**
- Electronegativity is the tendency of an atom to attract shared electrons in a chemical bond. It is influenced by the effective nuclear charge (Z_eff) and the distance of the valence electrons from the nucleus.

2. **Comparing Fluorine and Chlorine:**
- Fluorine (F) is located above chlorine (Cl) in Group 17 of the periodic table. As we move up a group, the size of the atom decreases, and the effective nuclear charge increases, leading to higher electronegativity.

3. **Conclusion on Assertion (A):**
- Since fluorine is smaller in size and has a higher effective nuclear charge compared to chlorine, it is indeed more electronegative than chlorine. Thus, Assertion (A) is **True**.

4. **Understanding Electron Affinity:**
- Electron affinity is the amount of energy released when an electron is added to a neutral atom in the gas phase. Generally, a higher electron affinity indicates a greater tendency to gain electrons.

5. **Comparing Electron Affinity of F and Cl:**
- While fluorine has a high electron affinity, chlorine actually has a slightly higher electron affinity than fluorine. This is due to the increased electron-electron repulsion in the smaller fluorine atom, which makes it less stable when gaining an additional electron.

6. **Conclusion on Reason (R):**
- Therefore, the statement that "F has a higher electron affinity than Cl" is **False**.

7. **Final Evaluation:**
- Since Assertion (A) is True and Reason (R) is False, the correct answer is that the Assertion is true, but the Reason is false.

### Final Answer:
- Assertion is True, Reason is False.

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