Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is:

Options

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

Answer

C

Explanation

As we move from Cl to I, the electron gain enthalpy (i.e., energy released in electron gain) become less and less negative due to a corresponding increase in the atomic size.
However, the electron gain enthalpy of F is less negative than that of Cl due to its small size. Thus, the negative electron gain enthalpy follows the order
`F lt Cl lt Br lt I`