Titanium (pronounce /taɪˈteɪniəm/) is a chemical element with the symbol Ti and atomic number 22. It is a light, strong, lustrous, corrosion-resistant (including to sea water and chlorine) transition metal with a grayish color. Titanium can be alloyed with iron, aluminium, vanadium, molybdenum, among other elements, to produce strong lightweight alloys for aerospace (jet engines, missiles, and spacecraft), military, industrial process (chemicals and petro-chemicals, desalination plants, pulp, and paper), automotive, agri-food, medical prostheses, orthopaedic implants, dental endodontic instruments and files), dental implants), sporting goods, jewelry, and other applications. Titanium was discovered in England by William Gregor in 1791 and named by Martin Heinrich Klaproth for the Titans of Greek mythology.