Molybdenum (Mo) - Element 42 | Properties & Electron Configuration
What is Molybdenum?
Molybdenum (Mo) is element 42, a transition metal in period 5, group 6. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁵ 5s¹.
| Atomic Number | 42 |
| Symbol | Mo |
| Atomic Mass | 95.95 u |
| Category | Transition Metal |
| Period | 5 |
| Group | 6 |
| Block | d |
| Electron Configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁵ 5s¹ |
| Short Config | [Kr] 4d⁵ 5s¹ |
| Electronegativity | 2.16 |
| Atomic Radius | 139 pm |
| Ionization Energy | 684 kJ/mol |
| Electron Affinity | 72 kJ/mol |
| Phase (STP) | Solid |
Electron Configuration
The full electron configuration of Molybdenum is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d⁵ 5s¹. In noble gas shorthand, this is written as [Kr] 4d⁵ 5s¹.
Molybdenum is a d-block element in group 6, period 5.
Periodic Trends
Electronegativity: Molybdenum has a Pauling electronegativity of 2.16. Within group 6, electronegativity generally decreases down the group.
Atomic Radius: 139 pm. Across period 5, atomic radius generally decreases left to right as nuclear charge increases.
Ionization Energy: 684 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Molybdenum on the Interactive Periodic TableRelated Topics
Chromium (Cr)
Properties of Chromium - same group as Molybdenum
Tungsten (W)
Properties of Tungsten - same group as Molybdenum
Seaborgium (Sg)
Properties of Seaborgium - same group as Molybdenum
Rubidium (Rb)
Properties of Rubidium - same period as Molybdenum
Strontium (Sr)
Properties of Strontium - same period as Molybdenum
Yttrium (Y)
Properties of Yttrium - same period as Molybdenum