Mo

Molybdenum is a chemical element; it has symbol Mo and atomic number 42. The name is derived from Ancient Greek μόλυβδος mólybdos, meaning lead, since its ores were sometimes confused with those of lead. Molybdenum minerals have been known throughout history, but the element was discovered in 1778 by Carl Wilhelm Scheele. The metal was first isolated in 1781 by Peter Jacob Hjelm.