Molybdenum , including Technical Data, Safety Data and its high purity properties, research, applications and other useful facts are discussed below. Scientific facts such as the atomic structure,ionization energy, abundance on Earth, conductivity and thermal properties are included.
Molybdenum has the third highest melting point of any element, exceeded only by tungsten and tantalum. Molybdenum is a catalyst in the oil refining. It has many other applications, including in catalysts, pigments, corrosion inhibitors and lubricants. It has a very high elastic modulus. Molybdenum is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity); metals in the form of foil, sputtering target, and rod, and compounds as submicron and nanopowder. It is used in steel alloys to add hardness and raise melting points. It is a component in Hastelloys brand steel. Molybdenum is used in nuclear reactors and aerospace components. Molybdenum is valuable as a catalyst in the refining of petroleum. It is used in high temperature filaments for electronics.
Molybdenum facts, research and properties are available for many specific states, forms and shapes on the product pages listed to the left. Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Nanoparticles and nanopowders provide ultra high surface area which nanotechnology research and recent experiments demonstrate function to create new and unique properties and benefits.
Abundance. The following table shows the abundance of molybdenum and each of its naturally occurring isotopes on Earth along with the atomic mass for each isotope.
|
Isotope
|
Atomic Mass
|
% Abundance on Earth
|
|
Mo-92
|
91.906810
|
14.84
|
|
Mo-94
|
93.905088
|
9.25
|
|
Mo-95
|
94.905841
|
15.92
|
|
Mo-96
|
95.904679
|
16.68
|
|
Mo-97
|
96.906021
|
9.55
|
|
Mo-98
|
97.905408
|
24.13
|
|
Mo-100
|
99.907477
|
9.63
|
The following table shows the abundance of Molybdenum present in the human body and in the universe scaled to parts per billion (ppb) by weight and by atom:
|
|
Typical Human Body
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Universe
|
|
by Weight
|
100 ppb
|
5 ppb
|
|
by Atom
|
7 ppb
|
0.1 ppb
|
Safety Data and Biological Role. The safety data for molybdenum metal, nanoparticles and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the left margin. Molybdenum compounds have a vital biological role in nitrogen fixation, enzymes, and nitrate reduction enzymes.
Ionization Energy. The ionization energy for molybdenum (the least required energy to release a single electron from the atom in it‘s ground state in the gas phase) is stated in the following table:
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1st Ionization Energy
|
684.32 kJ mol-1
|
|
2nd Ionization Energy
|
1559.21 kJ mol-1
|
|
3rd Ionization Energy
|
2617.67 kJ mol-1
|
Conductivity. As to molybdenum‘s electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ?C is 5.34 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 2.16. The thermal conductivity of molybdenum is 138 W m-1 K-1.
Thermal Properties. The melting point and boiling point for molybdenum are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
|
Heat of Fusion
|
27.6 kJ mol-1
|
|
Heat of Vaporization
|
589.9 kJ mol-1
|
|
Heat of Atomization
|
656.55 kJ mol-1
|
|
|
Formula
|
Atomic Number
|
Molecular Weight
|
Electronegativity (Pauling)
|
Density
|
Melting Point
|
Boiling Point
|
Vanderwaals radius
|
Ionic radius
|
Energy of first ionization
|
|
Mo
|
42
|
95.94 g.mol -1
|
1.8
|
10.2 g.cm-3 at 20 °C
|
2610 °C
|
4825°C
|
200.pm
|
0.068 nm (+4); 0.06 nm (+6)
|
684.32 kJ.mol-1
|
Oxides are available in forms including powders and dense pellets for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Molybdenum is available in soluble forms including chlorides, nitrates and acetates. These compounds are also manufactured as solutions at specified stoichiometries.
Molybdenum is a Block D, Group 6, Period 5 element. The number of electrons in each of Molybdenum‘s shells is 2, 8, 18, 13, 1 and its electronic configuration is [Kr] 4d5 5s1. In its elemental form molybdenum‘s CAS number is 7439-98-7. The molybdenum atom has a radius of 136.3.pm and it‘s Van der Waals radius is 200.pm. Molybdenum is toxic unless it is in small quantities.
All elemental metals, compounds and solutions may be synthesized in ultra high purity (e.g. 99.999%) for laboratory standards, advanced electronic, thin fillm deposition using sputtering targets and evaporation materials, metallurgy and optical materials and other high technology applications. Information is provided for stable (non-radioactive) isotopes. Organo-Metallic Molybdenum compounds are soluble in organic or non-aqueous solvents. See Analytical Services for information on available certified chemical and physical analysis techniques including MS-ICP, X-Ray Diffraction, PSD and Surface Area (BET) analysis.
The primary commercial source of molybdenum is molybdenite (MoS2), although it is also recovered as a byproduct of copper and tungsten mining. Molybdenum was first discovered by Carl Wilhelm in 1778. The origin of the name Molybdenum comes from the Greek word molubdos meaning lead.
