The correct order of electron affinity is

Options

A. `F gt Cl gt Br`
B. `F gt Cl gt Br`
C. `F lt Cl lt Br`
D. `F lt Cl lt Br`

Explanation

To determine the correct order of electron affinity for the halogens (Fluorine, Chlorine, Bromine, and Iodine), we can follow these steps:

### Step 1: Understand Electron Affinity
Electron affinity is the energy change that occurs when an electron is added to a neutral atom in the gas phase. Generally, a higher electron affinity means that an atom more readily accepts an electron.

### Step 2: Identify the Group
The halogens are located in Group 17 of the periodic table, which includes Fluorine (F), Chlorine (Cl), Bromine (Br), and Iodine (I).

### Step 3: General Trend in Electron Affinity
As we move down a group in the periodic table, the electron affinity typically decreases. This is because the atomic size increases, and the added electron is further from the nucleus, leading to a weaker attraction.

### Step 4: Analyze the Halogens
- **Fluorine (F)**: Despite being at the top of the group, it has a small atomic size. The small size leads to significant inter-electronic repulsion when an additional electron is added, which decreases its electron affinity.
- **Chlorine (Cl)**: Chlorine has a larger atomic size compared to fluorine, which reduces the inter-electronic repulsion. Therefore, it has a higher electron affinity than fluorine.
- **Bromine (Br)** and **Iodine (I)**: As we move down to bromine and iodine, the trend continues, with bromine having a higher electron affinity than iodine.

### Step 5: Establish the Correct Order
Based on the analysis:
1. Chlorine (Cl) has the highest electron affinity.
2. Fluorine (F) comes next, despite its position in the group.
3. Bromine (Br) follows.
4. Iodine (I) has the lowest electron affinity among these elements.

Thus, the correct order of electron affinity is:
**Cl > F > Br > I**

### Step 6: Identify the Correct Option
From the options given, we find that option C matches this order.

### Final Answer
The correct order of electron affinity is **Cl > F > Br > I**, and the correct option is **C**.

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