Element 42
Molybdenum
Transition metals
Molybdenum (Mo) is in the d-block of the periodic table — group 6, period 5.
Molybdenum is a chemical element with symbol Mo and atomic number 42.
Key data
- Atomic number
- 42
- Atomic mass
- 95.951 u
- Group / Period
- 6 / 5
- Block
- d-block
- Phase at STP
- Solid
- Density
- 10.28 g/cm³
- Melting point
- 2622.8 °C
- Boiling point
- 4638.9 °C
- Electron configuration
- [Kr] 4d5 5s1
Periodic table block
Molybdenum is in the d-block (group 6, period 5). Elements land in the d-block when their highest-energy electrons fill a d subshell — these are the transition metals in the middle of the table.
New to this? Periodic table blocks explained: s, p, d, and f
Common uses
- •High-strength steel
- •Catalysts
- •Plant nutrient
Discovery
Year: 1778
Discovered by: Carl Wilhelm Scheele
Frequently asked questions
What is the atomic number of Molybdenum?
Molybdenum has atomic number 42. Its symbol is Mo and its atomic mass is 95.951 u.
What category of element is Molybdenum?
Molybdenum is classified as transition metals. It sits in group 6, period 5 of the periodic table.
What block of the periodic table is Molybdenum in?
Molybdenum is in the d-block (group 6, period 5). Its highest-energy electrons occupy the d subshell — you can see this in its electron configuration, [Kr] 4d5 5s1.
What is Molybdenum used for?
Common uses of Molybdenum include: High-strength steel, Catalysts, Plant nutrient.
When was Molybdenum discovered?
Molybdenum was discovered in 1778 by Carl Wilhelm Scheele.
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