The electron gain enthalpy (in kJ/mol) of fluorine, chlorine, bromine and iodine, respectively, are:

🧠 Halogen $\Delta_{eg}H$ values in kJ/mol: F = $-328$, Cl = $-349$, Br = $-325$, I = $-296$. The order asked is F, Cl, Br, I — match the values to the elements in that exact order Most exothermic is Cl (not F!) due to F's $2p$ repulsion anomaly. Br is just below F in magnitude, and I is the least exothermic of the four halogens. Memorize the four numbers.

(Note: some sources cite F as $-333\,kJ/mol$. The textbook used here lists F = $-333$ — accept that for this question.)

🗺️ Match the option Question asks for F, Cl, Br, I in that order. F = $-333$, Cl = $-349$, Br = $-325$, I = $-296$. That is option (c): $-333, -349, -325, -296$.

Other options: (b) $-349, -333, -325, -296$ → this is Cl, F, Br, I order. Wrong sequence. (d) $-333, -325, -349, -296$ → this swaps Cl and Br. Cl is more exothermic than Br.

⚠️ The trap Option (b) puts $-349$ first — the most negative number sits at the front. Students assume "F is the smallest halogen, so F has the most negative EGE" and mark this. Wrong: the most negative value belongs to Cl (not F). Always remember the F anomaly: the $2p$ repulsion makes F's EGE LESS negative than Cl's.

$\boxed{\text{Answer: (c)}}$