bromine

Dark, reddish-brown, non-metallic element, a volatile liquid at room temperature, atomic number 35, relative atomic mass 79.904. It is a member of the halogen group, has an unpleasant odour, and is very irritating to mucous membranes. Its salts are known as bromides.

Bromine was formerly extracted from salt beds but is now mostly obtained from sea water, where it occurs in small quantities. Its compounds are used in photography and in the chemical and pharmaceutical industries.