bromine definition
bromine (Br) a corrosive, toxic red-brown liquid element of the halogen group. Its atomic number is 35; its atomic mass is 79.904. It exists naturally as a diatomic molecule, Br2. Bromine is used in industry, in photography, in the manufacture of organic chemicals and fuels, and in medications. Bromine gives off a red vapor that is extremely irritating to the eyes and the respiratory tract.