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’.

Sodium and chlorine react vigorously when heated, giving an orange flame and clouds of white sodium chloride.

Halogen heaters are radiant heaters. They utilise infrared radiation to work. The rods usually emit rays of heat that ...