n. A white, crystalline, brittle, highly diamagnetic metallic element used in alloys to form sharp castings for objects sensitive to high temperatures and in various low-melting alloys for fire-safety devices. Atomic number 83; atomic weight 208.98; melting point 271.3°C; boiling point 1,560°C; specific gravity 9.747; valence 3, 5. See Table at element.