The elements placed in group 7 (VIIA) of the periodic table are called halogens or salt producers. All these elements form salts called halides, e.g. NaCl, NaI, KCl, KI etc. Halogen is an ancient Greek word meaning 'salt producer'. Halogens have seven electrons in their valence shell and so are monovalent.
|Element||Atomic number||Electronic configuration||Valency||State||Colour|
|Fluorine||9||2, 7||-1||Gas||Greenish but more yellow|
|Chlorine||17||2, 8, 7||-1||Gas||Greenish yellow|
|Bromine||35||2, 8, 18, 7||-1||Liquid||Dark red liquid|
|Iodine||53||2, 8, 18, 18, 7||-1||Solid||Dark purple|
|Astatine||85||2, 8, 18, 32, 18, 7||-1||-||-|
|Bromine is the only Liquid non-metal. Iodine when heated undergoes sublimation.|