|a bluish-black element of the halogen group that sublimates into a violet irritating gas. Its compounds are used in medicine and photography and in dyes. The radioisotope iodine-131 (radioiodine), with a half-life of 8 days, is used in the diagnosis and treatment of thyroid disease. Symbol: I; atomic no: 53; atomic wt: 126.90447; valency: 1, 3, 5, or 7; relative density: 4.93; melting pt: 113.5°C; boiling pt: 184.35°C|
|[C19: from French iode, from Greek iōdēs rust-coloured, but taken to mean violet-coloured, through a mistaken derivation from ion violet]|
iodine i·o·dine (ī'ə-dīn', -dĭn, -dēn')
Symbol I A poisonous halogen element having compounds used as germicides, antiseptics, and food supplements, with radioactive isotopes, especially I 131, used in thyroid disease diagnosis and therapy. Atomic number 53; atomic weight 126.9045; melting point 113.7°C; boiling point 184.4°C; specific gravity (solid, at 20°C) 4.93; valence 1, 3, 5, 7.
A liquid containing iodine dissolved in ethyl alcohol, used as an antiseptic for wounds.
|iodine (ī'ə-dīn') Pronunciation Key
A shiny, grayish-black element of the halogen group. It is corrosive and poisonous and occurs in very small amounts in nature except for seaweed, in which it is abundant. Iodine compounds are used in medicine, antiseptics, and dyes. Atomic number 53; atomic weight 126.9045; melting point 113.5°C; boiling point 184.35°C; specific gravity (solid, at 20°C) 4.93; valence 1, 3, 5, 7. See Periodic Table.