Mark the element which shows only one oxidation state in its compounds

Options

A. `F`
B. `Cl`
C. `Br`
D. `I`

Answer

To determine which element shows only one oxidation state in its compounds from the given options (fluorine, bromine, and iodine), we can analyze the oxidation states of each element.

### Step-by-Step Solution:

1. **Identify the Elements**: The elements provided are fluorine (F), bromine (Br), and iodine (I).

2. **Understand Oxidation States**: Oxidation states indicate the degree of oxidation of an atom in a compound. Different elements can exhibit multiple oxidation states based on their electron configurations and bonding characteristics.

3. **Analyze Fluorine**:
- Fluorine is the most electronegative element in the periodic table.
- In compounds, fluorine typically exhibits an oxidation state of -1.
- For example, in hydrogen fluoride (HF), fluorine has an oxidation state of -1.
- The diatomic molecule (F2) has an oxidation state of 0.

4. **Analyze Bromine**:
- Bromine can exhibit multiple oxidation states, including +1, +3, +5, and +7.
- For example, in bromine trifluoride (BrF3), bromine has an oxidation state of +3.

5. **Analyze Iodine**:
- Similar to bromine, iodine can also exhibit multiple oxidation states, including +1, +3, +5, and +7.
- For instance, in iodine pentafluoride (IF5), iodine has an oxidation state of +5.

6. **Conclusion**:
- Among the three elements, only fluorine shows a consistent oxidation state of -1 in its compounds.
- Therefore, the element that shows only one oxidation state in its compounds is **fluorine**.

### Final Answer:
**Fluorine (F)** shows only one oxidation state in its compounds, which is -1.

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