Bromines

Bromines refers to the element bromine (Br), a member of the halogen group with atomic number 35. Bromine is notable for being a liquid at room temperature, existing as diatomic Br2. It is a reddish-brown liquid with a sharp, choking odor, highly reactive and toxic, requiring careful handling in laboratories and industry.

Physically, bromine melts at −7.2 °C and boils at 58.8 °C. Its liquid density is about 3.12 g/cm3, and it is moderately soluble in water while being more soluble in organic solvents. In pure form it is a corrosive reddish-orange liquid that readily forms bromides with metals and can react with hydrogen to yield hydrobromic acid (HBr).

Bromine is not found free in nature but occurs in seawater, brines, and mineral springs. Industrial bromine is produced mainly by oxidation of bromide-containing brines with chlorine, or by electrolysis of concentrated bromide brines, which releases Br2 at the anode.

Uses of bromine and many brominated compounds are widespread in industry. Bromine is used to manufacture brominated flame retardants, certain pharmaceuticals, and agrochemicals. Silver bromide has historical significance in photography. Brominated compounds also find applications in water treatment and in various organic synthesis reactions, including bromination of alkanes and alkenes.

Safety and environmental considerations are central to bromine handling. Bromine is highly toxic and corrosive, with exposure causing irritation to skin, eyes, and the respiratory tract. Some brominated organic compounds are persistent and bioaccumulative, leading to regulatory controls and ongoing environmental concern, particularly with certain brominated flame retardants.