Iodine and Iodine Molecule

**Symbol:** I

**Atomic number:** 53

**International title:** iodine

**General formula:** I₂

**Relative Atomic Weight:** 126,90

**Information:** Iodine is a toxic violet-black solid that sublimates under normal conditions (it passes into the gaseous phase). Gaseous iodine is purple coloured and, like other halogens, forms the two-atom molecules I₂ with a simple bond between the atoms. It is a typical non-metal.

**Use:**: Its five percent ethanol solution is called iodine tincture and used as a disinfectant. Iodine can be used to prove the presence of starch (added to starch it creates a dark blue complex). A solution of iodine and potassium iodide in water is called Lugol's solution (used for disinfection, starch detection).

**Occurrence:** The occurrence of iodine on Earth is very rare. It is only present in the form of compounds. The largest occurrence of iodine is in seawater. Iodine is a biogenic element (trace element).