They retain niche uses as antiepileptics.Īntoine Balard, one of the discoverers of bromineīromine was discovered independently by two chemists, Carl Jacob Löwig and Antoine Balard, in 18, respectively. 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 replacement by shorter-acting drugs. The role of biological organobromine compounds in sea life such as algae has been known for much longer. However, a clear biological role for bromide ions and hypobromous acid has recently been elucidated, and it now appears that bromine is an essential trace element in humans.
Large amounts of bromide salts are toxic from the action of soluble bromide ions, causing bromism. Bromine compounds are still used in well drilling fluids, in photographic film, and as an intermediate in the manufacture of organic chemicals. As a result, many organobromine compounds-such as the pesticide methyl bromide-are no longer used.
#Br element free#
The same property causes ultraviolet sunlight to dissociate volatile organobromine compounds in the atmosphere to yield free bromine atoms, causing ozone depletion.
This effect makes organobromine compounds useful as fire retardants, and more than half the bromine produced worldwide each year is put to this purpose. At high temperatures, organobromine compounds readily dissociate to yield free bromine atoms, a process that stops free radical chemical chain reactions. The mass of bromine in the oceans is about one three-hundredth that of chlorine.Īt standard conditions for temperature and pressure it is a liquid the only other element that is liquid under these conditions is mercury. Commercially the element is easily extracted from brine evaporation ponds, mostly in the United States, and Israel. While it is rather rare in the Earth's crust, the high solubility of the bromide ion (Br −) has caused its accumulation in the oceans. Isolated independently by two chemists, Carl Jacob Löwig (in 1825) and Antoine Jérôme Balard (in 1826), its name was derived from the Ancient Greek βρῶμος (meaning "stench"), referring to its sharp and pungent smell.Įlemental bromine is very reactive and thus does not occur free in nature, but in colourless soluble crystalline mineral halide salts, analogous to table salt. Its properties are intermediate between those of chlorine and iodine. It is the third-lightest halogen and is a volatile red-brown liquid at room temperature that evaporates readily to form a similarly coloured vapour. Bromine is a chemical element with the symbol Br and atomic number 35.
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