IODiin
Iodine is a chemical element with the symbol I and atomic number 53. It is a halogen and occurs as a dark violet-black solid at room temperature that readily sublimes to a violet gas. In nature it primarily forms diatomic molecules (I2) and forms a range of iodide compounds with metals and organic groups. The English name iodine has Greek origins related to its violet color.
Iodine is a trace element in seawater and rocks, and is concentrated commercially from brines and kelp-based
Iodine plays a critical biological role as a constituent of thyroid hormones, thyroxine (T4) and triiodothyronine
Applications include antiseptics such as povidone-iodine, diagnostic imaging using iodinated contrast media, and nuclear medicine therapy