I – iodine – consists of greyish-black crystals with a purple metallic luster and pungent odor. Its vapor has a characteristic purple color. Iodine mostly exists as diatomic molecules – I2. Iodine easily transitions from its solid to gaseous states and back, bypassing the liquid phase. Iodine is used in forensic science to detect fingerprints on papers such as banknotes; it dissolves primarily in fat deposits left by the fingers, revealing any traces that a perpetrator may have left behind. In medicine, an alcohol solution of iodine is used to disinfect the skin around damaged areas. Furthermore, iodine is categorized as a trace element and is present in all living organisms. It is a component of certain hormones that participate in many aspects of the body’s growth and metabolism