Which of the following elements has maximum electron affinity ?

Options

A. Cl
B. Br
C. I
D. F

Explanation

To determine which of the given elements has the maximum electron affinity, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Electron Affinity**:
- Electron affinity is defined as the amount of energy released when a neutral atom in the gas phase gains an electron to form a negative ion. The more energy released, the higher the electron affinity.

2. **Identify the Elements**:
- The elements in question are halogens: Fluorine (F), Chlorine (Cl), Bromine (Br), and Iodine (I).

3. **Trends in Electron Affinity**:
- Electron affinity generally increases across a period (from left to right) and decreases down a group (from top to bottom) in the periodic table.
- For halogens, as we move down the group from Fluorine to Iodine, the atomic size increases, leading to a decrease in effective nuclear charge felt by the incoming electron.

4. **Comparison of Electron Affinities**:
- Fluorine has a very small atomic size, which leads to significant inter-electronic repulsion when an additional electron is added. This repulsion can lower the energy released when gaining an electron.
- Chlorine, being larger than Fluorine, has less inter-electronic repulsion and can accommodate an additional electron more easily, resulting in a higher electron affinity.

5. **Conclusion**:
- Although Fluorine is expected to have a high electron affinity due to its position in the periodic table, Chlorine actually has a higher electron affinity than Fluorine due to the reasons discussed. Therefore, among the halogens, Chlorine has the maximum electron affinity.

### Final Answer:
**Chlorine (Cl) has the maximum electron affinity among the given elements.**

---