Group 7 halogensProperties and uses of the halogens
The Group 7 elements are also known as the halogens. The three common Group 7 elements are chlorine, bromine and iodine. The word âhalogenâ means 'salt former'.
This table summarises some of the properties and uses of three halogens:
Element
Appearance (room temperature)
Properties
Typical use
Chlorine
Yellow-green gas
Toxic â kills bacteria
Sterilising water
Bromine
Red-brown liquid
Toxic â kills bacteria
[Not required]
Iodine
Grey solid
Toxic â kills bacteria
Antiseptic used during hospital procedures
Element
Chlorine
Appearance (room temperature)
Yellow-green gas
Properties
Toxic â kills bacteria
Typical use
Sterilising water
Element
Bromine
Appearance (room temperature)
Red-brown liquid
Properties
Toxic â kills bacteria
Typical use
[Not required]
Element
Iodine
Appearance (room temperature)
Grey solid
Properties
Toxic â kills bacteria
Typical use
Antiseptic used during hospital procedures
Iodine forms a purple vapourVapour is a cloud of liquid particles. Steam is water vapour. when it is warmed.
All of the halogens exist as diatomic molecules. This means that the elements are made up of pairs of atoms that are chemically joined together (for example, fluorine exists as F2, chlorine as Cl2, bromine as Br2 and iodine as I2).