Group VII, The Halogens

All halogens form diatomic molecules

A halogen will displace a halogen which is below it from its salts because reactivity decreases down the group. ie Chlorine will displace bromine.

The reaction of silver nitrate with the halide is a test for halides: AgCl –white, AgBr –cream, and AgI –yellow.

Silver halides are used in photography as they darken in the presence of light.

Chlorine is used extensively for disinfection.