Molybdenum (Mo)

Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek Μόλυβδος molybdos, meaning lead, since its ores were confused with lead ores.

Atomic Number

42

Atomic Mass

95.95 u

Category

transition metal

Phase

solid

Density

10.28 g/cm³

Electron Shells

2, 8, 18, 13, 1

Atomic Structure

Protons: 42 • Electrons: 42 • Neutrons: Varies by isotope

Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d⁵

Discovery

1778 • Carl Wilhelm Scheele