Iodine is a chemical element with the symbol I and atomic number 53. It is a member of the halogen group in the periodic table and is the heaviest stable member of its group. Iodine is a nonmetallic element, known for its distinct bluish-black solid appearance and a lustrous sheen in its crystalline form. At room temperature, it sublimates readily to form a deep violet vapor.
Iodine has a very characteristic odor, which is described as sharp, clean, and somewhat acrid. The scent is pungent and can be overpowering, with a chemical sharpness that can irritate the mucous membranes. This strong odor is most notable in its elemental, gaseous state. In practical and commercial applications, iodine's smell is usually encountered in antiseptic preparations, where it is mixed with other compounds that might slightly alter its pure olfactory profile but generally retains its potent and distinctive smell.