Question

The electron gain enthalpies of halogens in kJ mol${}^{-1}$ are as given as F = -332, Cl = -349, Br = -324, I = -295. The less negative value for F as compared to that of Cl is due to :

• A. strong electron - electron repulsions in the compact 2p-sub shell of F
• B. weak electron - electron repulsions in the bigger 3p-sub shell of Cl
• C. smaller electronegativity value of F than Cl
• D. both (A) and (B)

Answer 1

Answer: (D)

both (A) and (B)

Due to small size of F atom, the electron-electron repulsions in compact 2-p subshell are large and hence the incoming electron is not accepted with the same ease as is the case with Cl (less electron - electron repulsions).