Halogen

The halogens or halogen elements are a series of nonmetal elements from Group 17 (old-style: VII or VIIA; Group 7 IUPAC Style) of the periodic table, comprising fluorine, F, chlorine, Cl, bromine, Br, iodine, I, astatine, At.

The group of halogens is the only group which contains elements in all three familiar states of matter at standard temperature and pressure.