Iodine (I)
Iodine (I)
Iodine is a halogen and was discovered in 1811.
A bluish-black and lustrous solid, iodine at ambient temperatures turns into a blue-violet gas with a distinct odor. It forms compounds, but is less reactive than other halogens. Iodine has some metallic properties, is slightly water-soluble, and forms a purple solution when dissolved in chloroform, carbon tetrachloride, or carbon disulfide.
Thirty iodine isotopes are recognized; only one stable isotope is found in nature. Artificial radioisotope I-131 is used to treat thyroid gland conditions. Iodine's compounds are used in organic chemistry and medicine.
Take care when handling and using iodine, which can cause lesions with skin contact and irritates the eyes and mucus membranes.