Iodine is a lustrous, purple-black metallic solid element represented by the symbol I and atomic number 53. It occurs in many oxidation states, including iodide, iodate and the various periodate anions. It is a nutritionally essential element, especially important in thyroid hormone synthesis. In solution, it has anti-infective properties and is used topically. This substance is the least abundant of the stable halogens, being the sixty-first most abundant element and is the heaviest essential mineral nutrient. Iodine can be found naturally in air, water and soil. The most important sources of natural iodine are the oceans.
1) Iodine is used in the preparation of certain drugs for treatment of thyroid. 2) It is used in the manufacture of some printing inks and dyes. 3) It is used as a supplement to feed animals. 4) It is also used as an ingredient for water purification.