Chemistry activity series lab

Question

An activity series could also be created for the halogens. Describe a set of tests that you could perform in order to accomplish this.

Answer 1

You could react each halogen with a metal, e.g. iron wool.

Fluorine should turn out to be the most reactive (dangerous, in fact).

The rank order of reactivity of the halogens would be F > Cl > Br > I

Reason: fluorine is the smallest of the halogens and thus the valence electrons are closer to the nucleus and more strongly attracted. All of the halogens are looking for an extra electron to complete their outer octet, and so the more strongly attracted the electrons, the more reactive.