Which can have both +ve and -ve oxdiation states in their compounds

Options

A. `F`
B. `I`
C. `Na`
D. `AI`

Answer

To determine which element can have both positive and negative oxidation states in their compounds, we can analyze the given options: chlorine, iodine, sodium, and aluminum.

### Step-by-Step Solution:

1. **Identify the Elements and Their Properties**:
- The elements provided are chlorine (Cl), iodine (I), sodium (Na), and aluminum (Al).

2. **Examine Chlorine**:
- Chlorine is a halogen and is known to be the most electronegative element.
- It typically exhibits a -1 oxidation state in compounds (e.g., NaCl).
- Chlorine does not commonly exhibit positive oxidation states in its compounds, so it cannot have both positive and negative oxidation states.

3. **Examine Iodine**:
- Iodine is also a halogen but has a larger atomic size compared to chlorine.
- It can exhibit multiple oxidation states: -1 (as in iodide), +1, +3, +5, and +7 in various compounds.
- Therefore, iodine can have both positive and negative oxidation states.

4. **Examine Sodium**:
- Sodium is an alkali metal and typically shows a +1 oxidation state (as in NaCl).
- It does not exhibit a negative oxidation state, so it cannot have both positive and negative oxidation states.

5. **Examine Aluminum**:
- Aluminum can exhibit oxidation states of +1, +2, and +3, with +3 being the most common.
- However, it does not show a negative oxidation state, so it cannot have both positive and negative oxidation states.

6. **Conclusion**:
- From the analysis, the only element that can exhibit both positive and negative oxidation states is iodine (I).

### Final Answer:
**Iodine (I)** can have both positive and negative oxidation states in its compounds.

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