The electron gain enthalpy (in kj / mol) of fluorine,
Question:

The electron gain enthalpy (in $\mathrm{kj} / \mathrm{mol}$ ) of fluorine, chlorine, bromine and iodine, respectively, are:

1.  $-296,-325,-333$ and $-349$

2. $-349,-333,-325$ and $-296$

3. $-333,-349,-325$ and $-296$

4. $-333,-325,-349$ and $-296$

Correct Option: , 3

Solution:

Chlorine has highest electron gain enthalpy (most negative) among the given elements, the electron gain enthalpy decreases down the group i.e., moves to least negative.