Download Element Fact Sheet – Bromine

Element Fact Sheet – Bromine
Bromine (from Greek: βρῶμος, brómos, meaning "strong-smelling" or "stench") is a chemical
element with the symbol Br, and atomic number of 35. It is a halogen. The element was isolated
independently by two chemists, Carl Jacob Löwig and Antoine Jerome Balard, in 1825–1826.
Elemental bromine is a fuming red-brown liquid at room temperature, corrosive and toxic, with
properties between those of chlorine and iodine. Free bromine does not occur in nature, but occurs
as colorless soluble crystalline mineral halide salts, analogous to table salt.
Bromine is rarer than about three-quarters of elements in the Earth's crust; however, the high
solubility of bromide ions has caused its accumulation in the oceans, and commercially the element
is easily extracted from brine pools, mostly in the United States, Israel and China. About 556,000
tonnes were produced in 2007, an amount similar to the far more abundant element magnesium.[4]
At high temperatures, organobromine compounds readily convert to free bromine atoms, a process
which has the effect of stopping free radical chemical chain reactions. This effect makes
organobromine compounds useful as fire retardants; more than half the bromine produced
industrially worldwide each year is put to this use. Unfortunately, the same property causes
sunlight to convert volatile organobromine compounds to free bromine atoms in the atmosphere,
and an unwanted side effect of this process is ozone depletion. As a result, many organobromide
compounds that were formerly in common use—such as the pesticide, methyl bromide—have been
abandoned. Bromine compounds are still used for certain purposes, however, including in well
drilling fluids, in photographic film, and as an intermediate in the manufacture of organic chemicals.
Bromine has been long believed to have no essential function in mammals, but recent research
suggests that bromine is necessary for tissue development. In addition, bromine is used
preferentially over chlorine by one antiparasitic enzyme in the human immune system.
Organobromides are needed and produced enzymatically from bromide by some lower life forms in
the sea, particularly algae, and the ash of seaweed was one source of bromine's discovery. As a
pharmaceutical, the simple bromide ion, Br–, has inhibitory effects on the central nervous system,
and bromide salts were once a major medical sedative, before being replaced by shorter-acting
drugs. They retain niche uses as antiepileptics.
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