Question

How would you account for the very high reactivity of halogens?

Answer 1

1. Halogens have low dissociation energy for their \[\ce{X - X}\] bonds, making it easy for their molecules to break into reactive atoms.
2. They have high negative electron gain enthalpies, which means they strongly attract electrons to form halide ions.
3. Their high electronegativity helps them readily gain electrons during chemical reactions.
4. Fluorine is the most reactive halogen because of these factors acting most strongly in it.
5. Reactivity decreases down the group from fluorine to iodine.