Group 7 – the halogens

The Group 7 elements are called the halogens. They are placed in the vertical column, second from the right, in the periodic table.

Periodic table with group 7 halogens highlighted: fluorine, chlorine, bromine, iodine and astatine

Chlorine, bromine and iodine are the three common Group 7 elements. Group 7 elements form salts when they react with metals. The term ‘halogen’ means 'salt former'.

Properties and uses of the halogens

This table summarises some of the properties and uses of three halogens:

ElementPropertiesTypical use
ChlorineGreen gasSterilising water
BromineOrange liquidMaking pesticides and plastics
IodineGrey solidSterilising wounds

Iodine forms a purple vapour when it is warmed.