Correct order of boiling point of halogens is

Options

A. `F_2 lt Cl_2 lt Br_2 lt I_2`
B. `Cl gt F_2 gt Br_2 gt I_2`
C. `F_2 gt Cl_2 gt Br_2 gt I_2`
D. `Cl_2 lt F_2 lt Br_2 lt I_2`

Answer

To determine the correct order of boiling points of halogens, we need to consider the trends in boiling points as we move down the group in the periodic table. The halogens include fluorine (F2), chlorine (Cl2), bromine (Br2), and iodine (I2).

### Step-by-Step Solution:

1. **Identify the Halogens**: The halogens are fluorine (F), chlorine (Cl), bromine (Br), and iodine (I). They exist as diatomic molecules (F2, Cl2, Br2, I2).

2. **Understand the Trend**: As we move down the group from fluorine to iodine, the size of the atoms increases. This increase in atomic size leads to an increase in the number of electrons, which in turn increases the strength of London dispersion forces (a type of van der Waals force).

3. **Boiling Point Trend**: The boiling point of a substance is influenced by the strength of intermolecular forces. In the case of halogens, as the size of the molecule increases, the London dispersion forces become stronger, resulting in higher boiling points.

4. **List the Halogens with Their Boiling Points**:
- F2 (Fluorine): -188 °C
- Cl2 (Chlorine): -34 °C
- Br2 (Bromine): 59 °C
- I2 (Iodine): 184 °C

5. **Arrange in Order**: Based on the boiling points listed:
- F2 < Cl2 < Br2 < I2

6. **Conclusion**: Therefore, the correct order of boiling points of halogens is:
- F2 < Cl2 < Br2 < I2

### Final Answer:
The correct order of boiling points of halogens is: **F2 < Cl2 < Br2 < I2**.