iodine

views updated

iodine (symbol I) Nonmetallic element, the least reactive of the halogen group. The black volatile solid gives a violet vapour and has an unpleasant odour that resembles chlorine. Iodine was discovered in 1811. Found in seawater, seaweeds and other plants, it is also extracted from Chile saltpetre and oil-well brine. Iodine is essential for the functioning of the thyroid gland. In medicine, it is used as an antiseptic. Properties: at.no. 53; r.a.m. 126.9; r.d. 4.93; m.p. 113.5°C (236.3°F); b.p. 184.4°C (363.9°F); most stable isotope I127 (100%).

More From encyclopedia.com