ELEMENTLE

Element 42 · Transition Metal

Molybdenum

Period 5 · Group 6

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.

Three reasons Molybdenum stands out

  1. 1

    Used to make steel stronger and withstand high temperatures.

  2. 2

    Its disulfide compound is used as a dry lubricant in conditions where oil would simply vaporise.

  3. 3

    Plants require enzymes containing this element to convert atmospheric nitrogen into a usable form.

Heat resistance with a biological twist

Molybdenum keeps strength at high temperatures, making its alloys useful in furnaces and engines. Living systems use molybdenum in enzymes that move oxygen atoms or process nitrogen compounds. Although essential only in traces, it helps close the nitrogen cycle on which ecosystems depend.

Molybdenum at a glance
Atomic number / protons42
SymbolMo
Family (Elementle)Transition Metal
Classification (PubChem)Transition metal
Period5
Group6
Atomic mass (u)95.95
Standard stateSolid
Electron configuration[Kr]5s1 4d5
Reported oxidation states+6
Electronegativity (Pauling)2.16
Atomic radius (pm)209
First ionization energy (eV)7.092
Electron affinity (eV)0.746
Density (g/cm³)10.2
Melting point2896 K (2,622.85 °C)
Boiling point4912 K (4,638.85 °C)
Discovery (PubChem)1778

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Molybdenum · Molybdenum on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.