Bromine

History

(Gr. bromos: stench) Discovered by Balard in 1826, but not prepared in quantity until 1860.[1]

Sources

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.[1]

Properties

General
Name : bromine
Symbol : Br
Atomic Number : 35
Chemical Series : Halogen
Block, Period : 17, 4
Appearance : gas: red brown, solid: metallic luster
Atomic Properties
Atomic Weight (amu) : 79.904
Covalent Radius (pm) : 114
Physical Properties
Matter : liquid (diamagnetic)
Density (kg/) : 3119
Hardness : n/a
Melting Point (K) : 265.8
Boiling Point (K) : 332
Evaporation Heat (kJ/mol) : 15.438
Fusion Heat (kJ/mol) : 5.286
Specific Heat (J/(kg*K) ) : 480
Miscellaneous
Electrical Conductivity (/m ohm) : n/a
Thermal Conductivity (W/(m*K) ) : 0.122

Bromine is the only nonmetallic liquid 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.[1]

Production

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.[1]

Uses

Bromine is used in making fumigants, flameproofing agents, water purification compounds, dyes, medicines, sanitizers, inorganic bromides for photography, etc. Organic bromides are also important.[1]

Notes

[1] From Los Alamos National Laboratory's Chemistry Division Website