A dense, volatile, corrosive, reddish-brown, nonmetallic liquid halogen element that exists as a diatomic molecule, Br₂ having a highly irritating vapor. Chiefly isolated from brines, it is used in producing fumigants, dyes, water purification compounds, and photographic chemicals. Atomic weight 79.904; atomic number 35; melting point -7.2°C; boiling point 58.8°C; density of gas 7.59 grams per liter; specific gravity (liquid, at 20°C) 3.12; valence 1, 3, 5, 7. See Periodic Table.