The correct electron affinity order of `N,O,S,Cl` is:

Options

A. `O lt N lt Cl lt S`
B. `Cl gt O gt S gt N`
C. `N lt O lt S lt Cl`
D. `N = Cl gt O = S`

Explanation

To determine the correct electron affinity order of Nitrogen (N), Oxygen (O), Sulfur (S), and Chlorine (Cl), 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, as we move from left to right across a period in the periodic table, the electron affinity increases. Conversely, as we move down a group, the electron affinity tends to decrease.

### Step 2: Arrange the Elements
We will arrange the elements according to their positions in the periodic table:
- Nitrogen (N) is in Group 15.
- Oxygen (O) is in Group 16.
- Sulfur (S) is in Group 16 (below Oxygen).
- Chlorine (Cl) is in Group 17.

### Step 3: Analyze Trends
- Moving from Nitrogen to Chlorine (left to right), we expect an increase in electron affinity.
- However, we need to consider the specific case of Oxygen and Sulfur. Although Oxygen is to the right of Nitrogen, it has a smaller atomic size and experiences significant inter-electronic repulsion in its 2p orbital, which reduces its electron affinity compared to Sulfur.

### Step 4: Compare Oxygen and Sulfur
- Sulfur, being larger and having less inter-electronic repulsion, has a higher electron affinity than Oxygen. Therefore, the order of electron affinity between these two is:
- Cl > S > O > N

### Step 5: Final Order
Putting it all together, the correct order of electron affinity for the elements N, O, S, and Cl is:
- Cl > S > O > N

### Conclusion
Thus, the correct electron affinity order is Cl > S > O > N.

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