Molybdenum
Molybdenum is a hard, silvery transition metal with an extremely high melting point, valued mainly as an alloying ingredient that makes steel tougher and more heat-resistant. Its name comes from an old Greek word for lead, a mix-up left over from before it was recognized as its own distinct element.
- Group · Period
- 6 · 5
- At room temp
- solid
- Melts at
- 2896 K
- Density
- 10.2 g/cm³
- Discovered
- 1778
Uses
The vast majority of molybdenum produced is used to strengthen steel: even small amounts alloyed in make steel notably tougher, harder and more resistant to heat and corrosion, which is why it shows up in tool steels, aircraft parts, oil and gas pipelines, and other demanding structural applications. Molybdenum disulfide, a soft, slippery compound, is used as a dry lubricant in situations where conventional oils would fail or evaporate, such as in a vacuum or under extreme pressure and temperature.
In the chemical industry, molybdenum compounds act as catalysts in petroleum refining, helping remove sulfur from fuels. Molybdenum is also an essential trace nutrient, required in tiny amounts by enzymes in plants and animals, including some involved in nitrogen processing.
History
Molybdenum’s mineral ore was known for centuries but was long mistaken for lead ore or graphite because of its similar look and greasy texture — its name comes from the Greek word molybdos, meaning lead. In 1778, Swedish chemist Carl Wilhelm Scheele examined the mineral molybdenite closely and demonstrated that it was chemically distinct from both lead and graphite, showing it contained an entirely new element. Scheele wasn’t able to isolate the pure metal himself, but a few years later, in 1781, his colleague Peter Jacob Hjelm succeeded in producing metallic molybdenum by heating its oxide with carbon, completing the element’s discovery.
Fun facts
- Molybdenum's main ore, molybdenite, was confused with both graphite and lead ore for centuries because of how similar it looked and felt.
- It has one of the highest melting points of any metal, letting molybdenum-containing steels stay strong under extreme heat.
- Molybdenum disulfide is used as a lubricant in situations where ordinary oil fails, including in vacuum environments and under very high pressure.
Frequently asked questions
Why does molybdenum's name come from a word for lead?
Its main ore, molybdenite, looks and feels a lot like graphite and lead ore, so for centuries all three were mistaken for the same material. The Greek word molybdos means lead, and the name stuck to the mineral even after Carl Wilhelm Scheele showed in 1778 that it actually contained a completely new element.
What is molybdenum mainly used for?
The great majority of molybdenum produced goes into alloying steel, where even small amounts make it significantly stronger, tougher and more resistant to heat and corrosion — properties valued in tools, pipelines, and aerospace components.
Is molybdenum an essential nutrient?
Yes, in trace amounts. Molybdenum is a required component of several enzymes in plants, animals and humans, though the amounts needed are extremely small and deficiency is rare in normal diets.
Compounds
5 notable compounds containing Mo
- (NH4)6Mo7O24salt
Ammonium heptamolybdate
A white, water-soluble salt that is the most common commercial form of molybdenum, widely used as an analytical reagent and micronutrient fertilizer.
Used for: Micronutrient fertilizer and reagent for detecting phosphate in analytical chemistry
- MoS2mineral
Molybdenum disulfide
A soft, dark gray solid with a layered structure similar to graphite, occurring naturally as the mineral molybdenite and prized as a dry lubricant.
Used for: Solid lubricant additive in greases and high-temperature/vacuum applications
- Mo(CO)6reagent
Molybdenum hexacarbonyl
A white, volatile solid in which a molybdenum atom is surrounded octahedrally by six carbon monoxide ligands, a classic and widely studied organometallic compound.
Used for: Catalyst and vapor-deposition precursor for depositing molybdenum films
- MoO3oxide
Molybdenum trioxide
A pale yellow solid formed by roasting molybdenite ore, and the principal industrial intermediate for producing molybdenum metal and other molybdenum chemicals.
Used for: Precursor for molybdenum metal and catalysts; glass and pigment colorant
- Na2MoO4salt
Sodium molybdate
A white, water-soluble salt used as a convenient soluble source of molybdenum in agriculture and as a corrosion inhibitor.
Used for: Trace-element fertilizer additive and corrosion inhibitor in cooling systems
Isotopes
39 known isotopes
Swipe to see all columns →
| Isotope | Natural abundance | Half-life | Decay mode | Mass excess | Binding energy / nucleon | Decay width |
|---|---|---|---|---|---|---|
| Mo-92 stable | 14.649% | Stable | — | -86,808.59 keV | 8,657.73 keV | — |
| Mo-94 stable | 9.187% | Stable | — | -88,414.08 keV | 8,662.33 keV | — |
| Mo-95 stable | 15.873% | Stable | — | -87,711.87 keV | 8,648.72 keV | — |
| Mo-96 stable | 16.673% | Stable | — | -88,794.89 keV | 8,653.99 keV | — |
| Mo-97 stable | 9.582% | Stable | — | -87,544.7 keV | 8,635.09 keV | — |
| Mo-98 stable | 24.292% | Stable | — | -88,115.98 keV | 8,635.17 keV | — |
| Mo-100 | 9.744% | 7.01E+18 Y | Double beta-minus decay (100%), Double beta-minus decay (100%) | -86,193.03 keV | 8,604.66 keV | 2.06 × 10-42 eV |
Show all 39 isotopes
| Mo-81 | — | 450 ns | ECP, Electron capture / beta-plus decay | -31,460 keV | 8,054 keV | 1.01 × 10-9 eV |
| Mo-82 | — | ? | Electron capture / beta-plus decay (100%), ECP | -40,370 keV | 8,163 keV | — |
| Mo-83 | — | 6 ms | Electron capture / beta-plus decay (100%) | -46,340 keV | 8,234 keV | 7.60 × 10-14 eV |
| Mo-84 | — | 2.3 s | Electron capture / beta-plus decay (100%), ECP | -54,170 keV | 8,325 keV | 1.98 × 10-16 eV |
| Mo-85 | — | 3.2 s | Electron capture / beta-plus decay (100%), ECP (0.14%) | -57,509.76 keV | 8,361.33 keV | 1.43 × 10-16 eV |
| Mo-86 | — | 19.1 s | Electron capture / beta-plus decay (100%) | -64,110.93 keV | 8,434.72 keV | 2.39 × 10-17 eV |
| Mo-87 | — | 14.1 s | Electron capture / beta-plus decay (100%), Beta-plus, proton emission (15%) | -66,884.82 keV | 8,462.42 keV | 3.24 × 10-17 eV |
| Mo-88 | — | 8.0 m | Electron capture / beta-plus decay (100%) | -72,686.55 keV | 8,523.91 keV | 9.50 × 10-19 eV |
| Mo-89 | — | 2.11 m | Electron capture / beta-plus decay (100%) | -75,014.94 keV | 8,544.99 keV | 3.60 × 10-18 eV |
| Mo-90 | — | 5.56 h | Electron capture / beta-plus decay (100%) | -80,172.51 keV | 8,597.03 keV | 2.28 × 10-20 eV |
| Mo-91 | — | 15.49 m | Electron capture / beta-plus decay (100%) | -82,208.83 keV | 8,613.63 keV | 4.91 × 10-19 eV |
| Mo-93 | — | 4.0E+3 Y | Electron capture (100%) | -86,807.08 keV | 8,651.41 keV | 3.61 × 10-27 eV |
| Mo-99 | — | 65.924 h | Beta-minus decay (100%) | -85,970.11 keV | 8,607.8 keV | 1.92 × 10-21 eV |
| Mo-101 | — | 14.61 m | Beta-minus decay (100%) | -83,519.95 keV | 8,572.92 keV | 5.20 × 10-19 eV |
| Mo-102 | — | 11.3 m | Beta-minus decay (100%) | -83,560.87 keV | 8,568.4 keV | 6.73 × 10-19 eV |
| Mo-103 | — | 67.5 s | Beta-minus decay (100%) | -80,954.33 keV | 8,538.27 keV | 6.76 × 10-18 eV |
| Mo-104 | — | 60 s | Beta-minus decay (100%) | -80,343.75 keV | 8,527.91 keV | 7.60 × 10-18 eV |
| Mo-105 | — | 36.3 s | Beta-minus decay (100%) | -77,330.79 keV | 8,494.86 keV | 1.26 × 10-17 eV |
| Mo-106 | — | 8.73 s | Beta-minus decay (100%) | -76,128 keV | 8,479.52 keV | 5.23 × 10-17 eV |
| Mo-107 | — | 3.5 s | Beta-minus decay (100%) | -72,544.98 keV | 8,442.22 keV | 1.30 × 10-16 eV |
| Mo-108 | — | 1.09 s | Beta-minus decay (100%) | -70,749.3 keV | 8,422.16 keV | 4.19 × 10-16 eV |
| Mo-109 | — | 0.61 s | Beta-minus decay (100%), Beta-minus, neutron emission (1.3%) | -66,659.29 keV | 8,381.42 keV | 7.48 × 10-16 eV |
| Mo-110 | — | 0.296 s | Beta-minus decay (100%), Beta-minus, neutron emission (2%) | -64,535.81 keV | 8,359.29 keV | 1.54 × 10-15 eV |
| Mo-111 | — | 186 ms | Beta-minus decay (100%), Beta-minus, neutron emission (12%) | -59,939.81 keV | 8,315.29 keV | 2.45 × 10-15 eV |
| Mo-112 | — | 120 ms | Beta-minus decay (100%) | -57,480 keV | 8,291 keV | 3.80 × 10-15 eV |
| Mo-113 | — | 80 ms | Beta-minus decay (100%), Beta-minus, neutron emission | -52,650 keV | 8,246 keV | 5.70 × 10-15 eV |
| Mo-114 | — | 58 ms | Beta-minus decay (100%), Beta-minus, neutron emission | -49,680 keV | 8,219 keV | 7.87 × 10-15 eV |
| Mo-115 | — | 45.5 ms | Beta-minus decay (100%), Beta-minus, neutron emission, B-2N | -44,550 keV | 8,173 keV | 1.00 × 10-14 eV |
| Mo-116 | — | 32 ms | B-2N, Beta-minus decay, Beta-minus, neutron emission | -41,210 keV | 8,143 keV | 1.43 × 10-14 eV |
| Mo-117 | — | 22 ms | B-2N, Beta-minus, neutron emission, Beta-minus decay | -35,689 keV | 8,096 keV | 2.07 × 10-14 eV |
| Mo-118 | — | 19 ms | Beta-minus decay (100%), B-2N, Beta-minus, neutron emission | -32,370 keV | 8,067 keV | 2.40 × 10-14 eV |
| Mo-119 | — | — | Beta-minus decay (100%), Beta-minus, neutron emission, B-2N | -26,580 keV | 8,019 keV | — |