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Transition metals

Molybdenum

A high-melting metal that strengthens steel and catalysts.

Atomic #42Mass95.95Blockd-blockPeriod5Group6
Mo42 · 95.95
3D Atom Explorer

Inside the Molybdenum atom

Switch between Bohr and Quantum Cloud modes to compare a simple teaching model with a more realistic probability-based view, and follow the guided tour to explore the Molybdenum atom step by step.

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Electron configuration

[Kr] 4d5 5s1

A neutral Molybdenum atom has 42 electrons (equal to its proton count). Choosing a different isotope above changes only the neutron count.

Shell distribution

Shell 12 e⁻Shell 28 e⁻Shell 318 e⁻Shell 413 e⁻Shell 51 e⁻

Electrons fill inner shells before outer ones; the outermost (valence) shell drives the element's chemistry.

Properties

Physical & atomic properties

State (room temp)
Solid
Melting point
2896 K (2623 °C)
Boiling point
4912 K (4639 °C)
Density
10.22 g/cm³
Electronegativity
2.16 Pauling
Atomic radius
145 pm
1st ionization energy
684 kJ/mol
Category
Transition metals
History

Discovery & naming

Discovered
1781
Discovered by
Peter Jacob Hjelm
Origin of name
Greek 'molybdos', meaning lead.

Notable uses

High-strength steel, catalysts, and lubricants.

Cosmic origin

Where Molybdenum comes from

Several comparable sources

Both slow neutron capture in dying stars and rapid capture in explosive events contribute meaningfully.

Simplified origin map — many elements form through more than one astrophysical pathway.

Summary

Atomic number
42
Atomic mass
95.95
Category
Transition metals
Group · Period
6 · 5
Block
d-block
Shells
2 · 8 · 18 · 13 · 1