Molybdenum
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. Molybdenum minerals have been known throughout history, but the element was discovered (in the sense of differentiating it as a new entity from the mineral salts of other metals) in 1778 by Carl Wilhelm Scheele.
A stylized shell model. Electrons are quantum objects, not particles following these literal paths. Sizes and motion are illustrative.
36 is the [Kr] core total across four shells.
At a glance
- Atomic number
- 42
- Atomic mass
- 95.951 u
- Phase
- Solid
- Density
- 10.28 g/cm³
- Melting point
- 2,896 K
- Boiling point
- 4,912 K
- First ionization energy
- 684.3 kJ/mol
- Electronegativity
- 2.16
- Electron affinity
- 72.1 kJ/mol
- Molar heat capacity
- 24.06 J/(mol·K)
- Period
- 5
- Appearance
- gray metallic
Conditions and isotopes affect measured properties. Some properties of short-lived elements are predicted. Electronegativity uses the Pauling scale.
Keep exploring
Explore the stories, imagery, and reference data in more depth. Properties with no value in the reference are marked unavailable.