Question

order of halogen reactivity

F , Cl ,Br, I

Answer 1

The order of reactivity for non-metals decreases from top to bottom in a group.
Therefore
I < Br < Cl < F (Ascending order)
       or
F > Cl > Br > I (Descending order)

But for metals, the reactivity increases from top to bottom in a group.

Hope my answer helps you.