A member of the halogen group of elements and the only liquid nonmetallic element. A heavy, reddish-brown liquid that volatilizes readily at room temperature to a poisonous, red vapor with a strong disagreeable odor. Symbol, Br. Obtained from natural brines from wells; little bromine is extracted today from seawater. Used in antiknock gasoline, fumigants, flameproofing agents, water purification compounds, dyes, medicinals, and sanitizers.