Highest electron affinity is shown by

Options

A. `F^(-)`
B. `Cl^(-)`
C. `Li^(+)`
D. `Na^(+)`

Answer

To determine which element has the highest electron affinity, we need to understand the concept of electron affinity and the periodic trends associated with it.

### Step-by-Step Solution:

1. **Definition of Electron Affinity**:
- Electron affinity is the amount of energy released when an electron is added to a neutral atom in the gaseous state. A higher electron affinity means that the atom releases more energy when it gains an electron.

2. **Periodic Trends**:
- Electron affinity generally increases across a period (from left to right) in the periodic table. This is due to the increase in nuclear charge, which attracts the added electron more strongly.
- Electron affinity generally decreases down a group (from top to bottom) because the atomic size increases, making it harder for the nucleus to attract the added electron.

3. **Identifying Elements**:
- Among the elements, noble gases typically have very low electron affinities because they already have a full valence shell and do not tend to gain electrons.
- Halogens, such as chlorine (Cl), fluorine (F), and bromine (Br), have high electron affinities because they are one electron short of a full valence shell and readily gain an electron.

4. **Comparing Electron Affinities**:
- Among the halogens, fluorine has the highest electron affinity, followed closely by chlorine. However, due to its smaller size, fluorine's electron affinity is more negative (indicating higher energy release) than that of chlorine.

5. **Conclusion**:
- Therefore, the element with the highest electron affinity is **Fluorine (F)**.