Halogens

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Halogens (Greek hals, “salt”; genes, “born”), in chemistry, group of five closely related chemically active elements—fluorine, chlorine, bromine, iodine, and astatine. The name halogen, or salt former, refers to the property of each of the halogens to form with sodium a salt similar to common salt (sodium chloride). Each member of the group has a valence of -1 and combines with metals to form halides, as well as with metals and nonmetals to form complex ions.

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