ETYM Greek als, alos, salt + -gen: cf. French halogčne.
Any of a group of five nonmetallic elements with similar chemical bonding properties: fluorine, chlorine, bromine, iodine, and astatine. They form a linked group in the periodic table of the elements, descending from fluorine, the most reactive, to astatine, the least reactive. They combine directly with most metals to form salts, such as common salt (NaCl). Each halogen has seven electrons in its valence shell, which accounts for the chemical similarities displayed by the group.
Any of the chemical elements fluorine or chlorine or bromine or iodine or astatine.
Any of a group of elements that unite directly with metal to form a salt, e.g. bromine, chlorine, fluorine, iodine. + prikaži više