Which of the following pairs is not correctly matched

Options

A. A halogen which is liquid at room temperature -Bromine
B. The most electronegative element - Fluorine
C. The most reactive halogen - Fluorine
D. The strongest oxidizing halogen - Iodine

Answer

To determine which of the following pairs is not correctly matched, we need to analyze the properties of halogens (Group 17 elements) and their respective characteristics.

### Step-by-Step Solution:

1. **Identify the Halogens**:
The halogens include fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).

2. **State at Room Temperature**:
- Fluorine (F) - Gas
- Chlorine (Cl) - Gas
- Bromine (Br) - Liquid
- Iodine (I) - Solid
- Astatine (At) - Solid (though it is rarely encountered)

**Conclusion**: The only halogen that is a liquid at room temperature is bromine (Br).

3. **Electronegativity**:
- The most electronegative element is fluorine (F).
- Electronegativity decreases down the group from fluorine to astatine.

**Conclusion**: The statement that the most electronegative element is fluorine is correct.

4. **Reactivity**:
- Fluorine is also the most reactive halogen. Reactivity decreases down the group.

**Conclusion**: The statement that fluorine is the most reactive element is correct.

5. **Strongest Oxidizing Agent**:
- Fluorine is the strongest oxidizing agent among all elements due to its high electronegativity and reactivity.

**Conclusion**: The statement that the strongest oxidizing agent is iodine is incorrect; it should be fluorine.

6. **Final Analysis**:
- The pairs that are correctly matched include:
- Bromine as a liquid at room temperature.
- Fluorine as the most electronegative element.
- Fluorine as the most reactive element.
- The incorrect pair is the one stating that iodine is the strongest oxidizing agent.

### Answer:
The pair that is not correctly matched is **the strongest oxidizing agent is iodine**; it should be **fluorine**.