Which of the following have maximum electron affinity?

Options

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

Answer

To determine which of the given elements has the maximum electron affinity among Fluorine (F), Chlorine (Cl), Bromine (Br), and Iodine (I), we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Electron Affinity**:
- Electron affinity is the energy change that occurs when an electron is added to a neutral atom in the gas phase. A higher electron affinity means that the atom has a greater tendency to accept an electron.

2. **Identifying the Group**:
- All the elements in question (F, Cl, Br, I) belong to Group 17 of the periodic table, known as the halogens.

3. **Trends in Atomic Size**:
- As we move down the group from Fluorine to Iodine, the atomic size increases due to the addition of electron shells. The order of size is:
- Iodine (largest) > Bromine > Chlorine > Fluorine (smallest).

4. **Electronegativity Consideration**:
- Electronegativity generally increases across a period and decreases down a group. Fluorine is the most electronegative element, while Iodine is the least among the halogens.

5. **Analyzing Electron Affinity**:
- Although Fluorine is highly electronegative, its small size leads to significant electron-electron repulsion when an additional electron is added to its already compact electron cloud. This repulsion reduces its electron affinity.
- Chlorine, being larger than Fluorine, has a more spacious 3p orbital, allowing it to accommodate an additional electron more easily, thus it has a higher electron affinity than Fluorine.

6. **Conclusion**:
- Among the halogens, Chlorine has the highest electron affinity due to its ability to accommodate an incoming electron without significant repulsion. Therefore, the answer is Chlorine (Cl).

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

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