Bromine - Br General Information Discovery Bromine was discovered by A.J. Balard in 1826 in Montpellier, France. Appearance Bromine is a red, dense liquid with a sharp, distinctive smell. It is poisonous and is extremely corrosive to skin. Source Bromine is extracted from natural brine deposits in the USA and elsewhere. It was the first element to be extracted from seawater but this is no longer economically viable as seawater contains only 65 parts per million of bromine. Uses Bromine is used in many areas such as agricultural chemicals, dyestuffs, chemical intermediates and flame-retardants. Most is used to prepare 1 ,2-di-bromoethane which is used as an anti-knock agent in combustion engines. Biological Role Bromine has no known biological role. It has an irritating effect on the eyes and throat, and produces painful sores when in contact with the skin. General Information Bromine combines readily with many elements. Like chlorine, it has a natural bleaching action.

	Physical Information
	Atomic Number		35
	Relative Atomic Mass (12C=12.000)		79.904
	Melting Point/K		266
	Boiling Point/K		332
	Density/kg m-3		3122 (293K)
	Ground State Electron Configuration		[Ar]3d104s24p5
	Electron Affinity(M-M-)/kJ mol-1		-324

	Key Isotopes
	nuclide	77Br	79Br	81Br	82Br
	atomic mass		78.918	80.916	81.917
	natural abundance	0%	50.69%	49.31%	0%
	half-life	57 h	stable	stable	35.5 h

Other Information
Enthalpy of Fusion/kJ mol-1		10.8
Enthalpy of Vaporisation/kJ mol-1		30.5
Oxidation States
main	Br -1, Br+5
others	Br+1, Br+3, Br+4, Br+7
Covalent Bonds /kJ mol-1
Br - H	366
Br - C	285
Br - O	234
Br - F	285
Br - Br	193
Br - B	410
Br - Si	310
Br - P	264

	Ionisation Energies/kJ mol-1
	M - M+	1139.9
	M+ - M2+	2104
	M2+ - M3+	3500
	M3+ - M4+	4560
	M4+ - M5+	5760
	M5+ - M6+	8550
	M6+ - M7+	9940
	M7+ - M8+	18600
	M8+ - M9+	23900
	M9+ - M10+	28100