Which is not oxidised by `MnO_(2)^(-7)`

Options

A. `I_(2)`
B. F
C. I
D. Cl

Answer

To determine which substance is not oxidized by \( \text{MnO}_2^{-7} \), we need to analyze the oxidation behavior of the halogens provided in the options: fluorine, chlorine, and iodine.

### Step-by-Step Solution:

1. **Identify the Nature of \( \text{MnO}_2^{-7} \)**:
- \( \text{MnO}_2^{-7} \) is a strong oxidizing agent. This means it has a tendency to gain electrons and oxidize other substances.

2. **Consider the Halogens**:
- The halogens in the options are fluorine (F), chlorine (Cl), and iodine (I). We need to determine their ability to lose electrons (i.e., get oxidized).

3. **Analyze Fluorine**:
- Fluorine has 7 electrons in its outermost shell and is the most electronegative element. Due to its small atomic size and high electronegativity, it is very difficult to remove an electron from fluorine. Therefore, fluorine does not get oxidized easily.

4. **Analyze Chlorine**:
- Chlorine has a larger atomic size compared to fluorine and can lose an electron more easily than fluorine. Thus, chlorine can be oxidized by \( \text{MnO}_2^{-7} \).

5. **Analyze Iodine**:
- Iodine is even larger than chlorine and can also lose an electron relatively easily. Therefore, iodine can also be oxidized by \( \text{MnO}_2^{-7} \).

6. **Conclusion**:
- Since fluorine is the most difficult to oxidize due to its small size and high electronegativity, it is the substance that is **not oxidized** by \( \text{MnO}_2^{-7} \).

### Final Answer:
**Fluorine (F) is not oxidized by \( \text{MnO}_2^{-7} \).**