Element 42
Molybdenum (Mo)
Molybdenum (Mo) is element 42 of the periodic table, a transition metal in period 5, group 6 (d-block) with an atomic mass of 95.95 and is a solid at standard conditions.
At a glance
- Atomic number
- 42
- Symbol
- Mo
- Atomic mass
- 95.95 u
- Category
- Transition metals
- Period
- 5
- Group
- 6
- Block
- d-block
- Phase at STP
- solid
Electron structure
- Electron configuration
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d5 5s1
- Shorthand configuration
- [Kr] 4d5 5s1
- Electrons per shell
- 2, 8, 18, 13, 1
- Oxidation states
- -4, -2, -1, +1, +2, +3, +4, +5, +6
Physical properties
- Melting point
- 2896 K
- Boiling point
- 4912 K
- Density
- 10.22 g/cm3
- Phase
- solid
Atomic properties
- Electronegativity (Pauling)
- 2.16
- Atomic radius
- 190 pm
- Covalent radius
- 154 pm
- First ionization energy
- 684 kJ/mol
- Electron affinity
- 72 kJ/mol
Notable isotopes
| Isotope | Mass | Abundance | Stability |
|---|---|---|---|
| Mo-98 | 97.90541 | 24.13% | Stable |
Common uses
- Steel alloys
- Catalysts
- Lubricants
- Electronics
Discovery
- Year
- 1781
- Discovered by
- Carl Wilhelm Scheele
- Country
- Sweden