- published: 08 Apr 2015
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The halogens or halogen elements are a series of nonmetal elements from Group 17 IUPAC Style (formerly: VII, VIIA) of the periodic table, comprising fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). The artificially created element 117, provisionally referred to by the systematic name ununseptium, may also be a halogen.
The group of halogens is the only periodic table group which contains elements in all three familiar states of matter at standard temperature and pressure.
In 1842 the Swedish chemist Baron Jöns Jakob Berzelius proposed the term "halogen" – ἅλς (háls), "salt" or "sea", and γεν- (gen-), from γίγνομαι (gígnomai), "come to be" – for the four elements (fluorine, chlorine, bromine, and iodine) that produce a sea-salt-like substance when they form a compound with a metal. Earlier, in 1811, the word "halogen" had been proposed as a name for the newly discovered element chlorine, but Davy's proposed term for this element eventually won out.
Like other groups, the candidates of this family show patterns in its electron configuration, especially the outermost shells resulting in trends in chemical behavior: