With reputation of being an elenment of life and wisdom,iodine id the essential element for human body and the plant growth.The product is widely used in food,pharmaceutical,metalllurgy,agriculture,dyestuff,high-tech and many other fields. molecular weight:I2，molecular formula:253.8 This product is greyish black or bluish black crystal flaks of lump with a metallic luster,the nature is heavy,vrispy and with special odor,It can volatilize at room temperature.. Applications： Pharmaceutical industry：Sterlization and disinfection reagent:tincture of iodine； To synthesize potassium iodide,sodium ioide,compound iodine solution ldizeed oil iodide for making the developing agent of x light.。 Food industtry：The synthesis of sodium iodate,potassium iodate etc. Others：Used as catalyst in chemical and metallurgical industry. Agriculturally, iodine is the material for pesticide,4-iodinephenoxy acetic,for example.Iodine is the material synthesize organic dyestuffs.In lighting industry,tungsten-iodine lamps,colour light lamps.