Molybdenum
Molybdenum is a transition metal with a high melting point and useful catalytic properties.
Molybdenum helps alloys stay strong when conditions become demanding.
Explore Molybdenum's atom- Atomic number
- 42
- Standard atomic weight
- 95.95(1)
- Family
- Transition metal
- Period
- 5
- Group
- 6
- Standard state
- Solid
In everyday life
Molybdenum is added to some steels and used in industrial catalysts.
Something to remember
Molybdenum is also a trace element used by enzymes in living organisms.
Meet its electrons
[Kr] 5s1 4d5
Published neutral-atom ground-state configuration; excited atoms and ions can differ.
Electrons per shell: 2 · 8 · 18 · 13 · 1.
The playground shows an illustrative shell model. Real electrons are described by quantum orbitals, rather than tiny planets traveling along fixed paths.
A connection to explore
Molybdenum and tungsten are members of the same group with high melting points.
Meet Tungsten (W)Properties and conditions
- Standard atomic weight
- 95.95(1)CIAAW 2024 standard atomic weight (dimensionless). Parentheses give uncertainty in the last quoted digits. Source flags: g.CIAAW standard atomic weights ↗ · Retrieved 2026-10-15
- Standard state
- SolidPubChem classification, including explicit predictions where stated. Reference temperature and pressure are not supplied in the table.PubChem periodic table ↗ · Retrieved 2026-10-15
- First ionisation energy
- 7.092 eVEnergy to remove the first electron from an isolated neutral gas-phase atom. Uncertainty is not supplied.PubChem periodic table ↗ · Retrieved 2026-10-15
- Electronegativity
- 2.16 Pauling scaleA dimensionless relative measure; values depend on the chosen scale. Uncertainty is not supplied.PubChem periodic table ↗ · Retrieved 2026-10-15
- Melting point
- 2896 KPubChem reported value. Pressure, allotrope and measurement uncertainty are not specified in the table; consult the cited source.PubChem periodic table ↗ · Retrieved 2026-10-15
- Boiling point
- 4912 KPubChem reported value. Pressure and measurement uncertainty are not specified in the table; consult the cited source.PubChem periodic table ↗ · Retrieved 2026-10-15
- Density
- 10.2 g/cm³PubChem reported value. Temperature, pressure, allotrope and measurement uncertainty are not specified in the table; gas densities are especially condition-dependent.PubChem periodic table ↗ · Retrieved 2026-10-15
- Oxidation states
- +6Selected PubChem oxidation states; formal electron bookkeeping, not a list of stable free-ion charges or every possible compound.PubChem periodic table ↗ · Retrieved 2026-10-15
- Discovery
- 1778PubChem discovery attribution. Ancient knowledge and competing priority claims cannot always be represented by a single year.PubChem periodic table ↗ · Retrieved 2026-10-15
- Atomic radius
- 209 pmPubChem tabulated radius. Radius definitions depend on bonding and convention; measurement definition and uncertainty are not supplied in this table.PubChem periodic table ↗ · Retrieved 2026-10-15
- Electron affinity
- 0.746 eVPubChem reported gas-phase electron affinity. Sign conventions and electronic states matter; uncertainty is not supplied in this table.PubChem periodic table ↗ · Retrieved 2026-10-15
Isotopes, abundance and decay
Isotopes share a proton count but have different neutron counts. This selection includes naturally tabulated compositions and a reference isotope for other elements. It is not a list of every known isotope.
Explore 7 isotopes of Mo
| Isotope | Relative atomic mass | Natural fraction | Half-life | Decay |
|---|---|---|---|---|
| Mo-92 | 91.90680796(84) | 0.1453(30) | No decay observed | ;2β+ ? |
| Mo-94 | 93.90508490(48) | 0.0915(9) | No decay observed | No decay tabulated |
| Mo-95 | 94.90583877(47) | 0.1584(11) | No decay observed | No decay tabulated |
| Mo-96 | 95.90467612(47) | 0.1667(15) | No decay observed | No decay tabulated |
| Mo-97 | 96.90601812(49) | 0.0960(14) | No decay observed | No decay tabulated |
| Mo-98 | 97.90540482(49) | 0.2439(37) | No decay observed | ;2β− ? |
| Mo-100 | 99.9074718(11) | 0.0982(31) | 7.07 Ey (uncertainty 0.14) | ;2β−=100 |
Fractions use NIST’s terrestrial isotopic compositions, which can vary by sample. Parentheses denote uncertainty in the last digits. Half-lives and decay branches use NUBASE2020; # marks estimates, >/< mark limits. “No decay observed” follows that evaluation and does not prove permanent stability. Decay branch intensities are percentages; SF means spontaneous fission, EC electron capture, IT an isomeric transition.
Follow the science
Use these original references to explore the data and context. Atomic weights can vary with isotope composition; values for elements without stable isotopes may describe a representative isotope rather than a standard atomic weight.