Correct order of decreasing electron affinities of group VII is:

Explanation

The correct order of decreasing electron affinities for Group VII (halogens) is:Cl > F > Br > IHere's why:General Trend: Electron affinity generally decreases down a group in the periodic table. This is because the atomic radius increases, and the added electron is further from the nucleus, experiencing weaker attraction. Fluorine Anomaly: Fluorine is an exception to this trend. Although it's smaller than chlorine, it has a lower electron affinity. This is attributed to the small size of the fluorine atom and its high electron density. The added electron experiences significant repulsion from the existing electrons in the small 2p subshell, making the addition of an electron less favorable than in chlorine, which has a larger 3p subshell. Therefore, chlorine has the highest electron affinity among the halogens, followed by fluorine, then bromine, and finally iodine.