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Chromium , including Technical Data, Safety Data and its High Purity propertiesresearch, applications and other useful facts are discussed below. Scientific facts such as the atomic structure,ionization energyabundance on Earthconductivity and thermal properties are included. 

Chromium is highly resistant to corrosion. This has led to its use in numerous alloying and steel producing applications. When chromium is added to glass or ceramic glazes, it produces a brilliant green. Chromium 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 also used as a paint pigment for this purpose.Although chromium metal is an essential trace element, hexavalent chromium (Cr(VI)) is especially toxic and carcinogenic. Recently, chromites have formed the basis for cathode compositions for oxygen generation and fuel cell applications. 

Chromium facts, including appearance, CAS #, and molecular formula and safety data, 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. 

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. Chromium is available in soluble forms including chlorides, nitrates and acetates. These compounds are also manufactured as solutions at specified stoichiometries. 

Chromium is a Block D, Group 6, Period 4 element. The number of electrons in each of Chromium‘s shells is 2, 8, 13, 1 and its electronic configuration is [Ar] 3d5 4s1. In its elemental form chromium‘s CAS number is 7440-47-3. The chromium atom has a radius of and it‘s Van der Waals radius is Hexavalent chromium is toxic. 

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 andevaporation materials, metallurgy and optical materials and other high technology applications. Information is provided for stable (non-radioactive) isotopesOrgano-Metallic Chromium 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. 

Chromium was first discovered by Anders Ekeberg in 1802. The most common source of Chromium is chromite ore (FeCr2O4). Due to its various colorful compounds, Chromium was named after the Greek word ‘chroma‘ meaning color.

Abundance. The following table shows the abundance of chromium and each of its naturally occurringisotopes on Earth along with the atomic mass for each isotope.
Isotope Atomic Mass % Abundance on Earth
Cr-50 49.946050 4.35
Cr-52 51.940512 83.79
Cr-53 52.940654 9.50
Cr-54 53.938885 2.37

The following table shows the abundance of Chromium present in the human body and in the universe scaled to parts per billion (ppb) by weight and by atom:
  Typical Human Body Universe
by Weight 30 ppb 15000 ppb
by Atom 4 ppb 400 ppb

Safety Data and Biological Role. The safety data for chromium metalnanoparticles 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. Chromium compounds in trace quantities have an essential biological role in glucose metabolism. 

Ionization Energy. The ionization energy for chromium (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:
1st Ionization Energy 652.87 kJ mol-1
2nd Ionization Energy 1590.64 kJ mol-1
3rd Ionization Energy 2987.21 kJ mol-1

Conductivity. As to chromium‘s electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ?C is 12.9 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 1.66. The thermal conductivity of chromium is 93.7 W m-1 K-1. 

Thermal Properties. The melting point and boiling point for chromium are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
Heat of Fusion 15.3 kJ mol-1
Heat of Vaporization 341.8 kJ mol-1
Heat of Atomization 394.51 kJ mol-1

Formula Atomic Number Molecular Weight Electronegativity (Pauling) Density Melting Point Boiling Point Vanderwaals radius Ionic radius Energy of first ionization
Cr 24 51.996 g.mol-1 1.6 7.19 at 20 °C 1907 °C 2672 °C 0.061 nm (+3) ; 0.044 nm (+6) 652.87 kJ.mol-1