Question

explain the gradation in reactivity of
halogen family

Answer 1

All halogens have one electron less in their outermost shell.

one shell increses top to bottom.so attraction between nucleus and outermost shell decreases.

so in halogens family reactivity decreases from top to bottom.

Flourine is most reactive and astatine is least reactive.

Answer 2

F > Cl > Br > I > At . so reactivity decrease as we go down..