Which of the following is correct order of EA.

Options

A. N `lt` C `lt` O `lt` F
B. F `gt` Cl`gt` Br`gt` I
C. Cl `gt` F `gt` Br `gt` l
D. C`lt`N`lt`O`lt`F

Answer

To determine the correct order of electron affinity (EA) among the given elements, we need to understand the concept of electron affinity and how it varies across the periodic table.

### 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 (more negative) electron affinity indicates a greater tendency to gain an electron.

2. **Trend Across the Periodic Table**:
- **Left to Right in a Period**: As we move from left to right across a period, the atomic size decreases due to increasing nuclear charge. This leads to a stronger attraction between the nucleus and the added electron, resulting in higher electron affinity.
- **Top to Bottom in a Group**: As we move down a group, the atomic size increases, and the added electron is further from the nucleus. This results in lower electron affinity.

3. **Analyzing the Given Elements**:
- Let's consider the elements in the question: Fluorine (F), Oxygen (O), Carbon (C), and Nitrogen (N).
- **Fluorine (F)**: Has the highest electron affinity because it achieves a stable noble gas configuration (Neon) when it gains an electron.
- **Oxygen (O)**: Has a high electron affinity but less than Fluorine.
- **Carbon (C)**: Gains an electron to form a half-filled p subshell (2p2 to 2p3), which is relatively stable but has less electron affinity than Oxygen.
- **Nitrogen (N)**: Gains an electron to form 2p4, which is less stable than Carbon's configuration, resulting in the lowest electron affinity among these elements.

4. **Correct Order of Electron Affinity**:
- Based on the analysis, the correct order of electron affinity from highest to lowest is:
- **Fluorine (F) > Oxygen (O) > Carbon (C) > Nitrogen (N)**

5. **Conclusion**:
- Therefore, the correct answer is that the order of electron affinity is:
- **Fluorine > Oxygen > Carbon > Nitrogen**.