- Group 7- The Halogens
- The halogens are non-metallic elements in group 7 of the periodic table.
- The exist as small molecules made up if pairs of atoms. They have low melting and boiling points that increase going down the group.
- At room temperature fluorine is a pale yellow gas, chlorine is a green gas, bromine is a red-brown liquid and iodine is a grey solid- iodine easily vaporises into a violet gas.
- All of the halogens have seven electrons in their outer shell.
- The halogens form ionic compounds with metals in which the halide ions have a charge of 1-.
- The halogens also bond covalently with non-metals, forming molecules
- The reactivity of the halogens decreases going down the group. A more reactive halogen is able to displace and less reactive halogen from an aqueous solution of a halide compound.