Element:	Bromine
Symbol:	Br
Atomic number:	35
Atomic weight:	79.904(1)
Electron configuration:	[Ar] 3d10 4s2 4p5
Ground level:	2Po3/2
Ionization potential:	11.8138 ev
Physical form:	Red liquid
Melting point:	-7.2°C
Boiling point:	58.8°C
Critical temperature:	315°C
Density:	3.1028 g/cm3
Specific heat:	0.474 J/g•K
Valence	1, 5, -1

Origin of name: Gr. bromos, stench

Discovered by Balard in 1826, but not prepared in quantity until 1860.

A member of the halogen group of elements, it is obtained from natural brines from wells in Michigan and Arkansas. Little bromine is extracted today from seawater, which contains only about 85 ppm.

Bromine is the only liquid nonmetallic element. It is a heavy, mobile, reddish-brown liquid, volatilizing readily at room temperature to a red vapor with a strong disagreeable odor, resembling chlorine, and having a very irritating effect on the eyes and throat; it is readily soluble in water or carbon disulfide, forming a red solution, is less active than chlorine but more so than iodine; it unites readily with many elements and has a bleaching action; when spilled on the skin it produces painful sores. It presents a serious health hazard, and maximum safety precautions should be taken when handling it.

Much of the bromine output in the U.S. was used in the production of ethylene dibromide, a lead scavenger used in making gasoline antiknock compounds. Lead in gasoline, however, has been discontinued, due to environmental considerations. This will greatly affect future production of bromine. Bromine is also used in making fumigants, flameproofing agents, water purification compounds, dyes, medicinals, sanitizers, inorganic bromides for photography, etc. Organic bromides are also important.

Natural bromine is made of two isotopes, ⁷⁹Br and ⁸¹Br. Thirty-four isotopes and isomers are known.

Bromine (99.8%) costs about $70/kg.