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Author: Robert Husted, Mollie Boorman

Atomic Number 35
Atomic Symbol Br
CAS ID No. 7726-95-6
Atomic Weight 79.9090 amu
Electron Configuration [Ar] 3d10 4s2 4p5
Melting Point -7.1 C
Boiling Point 59 C
Density 3.120 g/cm3

(Gr. bromos: stench) Discovered by Balard in 1826, but not prepared in quantity until 1860.


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


Ref.: Wikimedia Commons, user Tomihahndorf
Bromine is the only  nonmetallic liquid element. It is a heavy, mobile, reddish-brown liquid, volatilizing readily at room temperature to a red vapor (see photo at the right) 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 anti-knock compounds. Lead in gasoline, however, has been drastically reduced due to environmental considerations. This will greatly affect future production of bromine.


Bromine is used in making fumigants, flameproofing agents, water purification compounds, dyes, medicines, sanitizers, inorganic bromides for photography, etc. Organic bromides are also important.

Last Update: 2011-02-16