Molybdenum (Mo)
Transition metal · d-block · period 5 · group 6
Hard, silvery-grey metal with a very high melting point.
Molybdenum (symbol Mo) is chemical element number 42, a transition metal in group 6, period 5 of the periodic table. Its standard atomic weight is 95.95 and its electron configuration is [Kr] 4d5 5s1. At room temperature it is a solid. Its name comes from the Greek for 'lead', which its ore was mistaken for.
Properties
| Atomic number | 42 |
|---|---|
| Atomic mass | 95.95 |
| Category | Transition metal |
| Block | d-block |
| Group · Period | 6 · 5 |
| Electron configuration | [Kr] 4d5 5s1 |
| Electrons per shell | 2, 8, 18, 13, 1 |
| State at 25 °C | solid |
| Melting point | 2896 K |
| Boiling point | 4912 K |
| Density | 10.28 g/cm³ |
| Electronegativity (Pauling) | 2.16 |
| Radioactive | No |
| Origin | primordial |
| Discovered | 1778 · Carl Wilhelm Scheele |
Key facts about Molybdenum
- Its name comes from the Greek for 'lead', which its ore was mistaken for.
- Keeps its strength at red heat, so it is used in furnace parts and rocket nozzles.
- Molybdenum disulfide is a dry lubricant that works in a vacuum and under huge pressure.
- An essential trace element for enzymes that fix nitrogen in plants.
What Molybdenum is used for
High-strength and stainless steels, furnace and aerospace parts, dry lubricants, catalysts, pigments.
Where it sits in the periodic table
Molybdenum is in group 6, period 5, of the d-block. Its electron configuration [Kr] 4d5 5s1 means its outermost shell holds 1 electron, which is what places it here and explains much of its chemistry. See Molybdenum on the interactive table →
Molybdenum — frequently asked questions
What is Molybdenum used for?
High-strength and stainless steels, furnace and aerospace parts, dry lubricants, catalysts, pigments.
Is Molybdenum radioactive?
No. Molybdenum has at least one stable isotope and is not radioactive.
What is the electron configuration of Molybdenum?
Molybdenum has the electron configuration [Kr] 4d5 5s1, which is 2, 8, 18, 13, 1 electrons per shell.
What group and period is Molybdenum in?
Molybdenum is in group 6, period 5, in the d-block. Its outer shell holds 1 electron.
Who discovered Molybdenum?
Molybdenum was discovered in 1778 by Carl Wilhelm Scheele.