Chromium information, 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.
 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 124.9.pm and it's Van der Waals radius is 200.pm. 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 and  evaporation materials, metallurgy and optical materials and other high technology applications. Information is provided for stable (non-radioactive) isotopes. Organo-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.
 chrome |
 Chrom |
 cromo |
 Crômo |
 cromo |
 Krom |
Abundance. The following table shows the abundance of chromium and each of its naturally occurring isotopes 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 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. 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 ºC 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 |
Recent Research & Development for Chromium
Fluoride-bridged {Ln(2)Cr(2)} polynuclear complexes from semi-labile mer-[CrF(3)(py)(3)] and [Ln(hfac)(3)(H(2)O)(2)].
Thuesen CA, Pedersen KS, Schau-Magnussen M, Evangelisti M, Vibenholt J, Piligkos S, Weihe H, Bendix J.
Dalton Trans. 2012 Aug 10. [Epub ahead of print]
PMID:
22878363
[PubMed - as supplied by publisher]
Sorption media for stormwater treatment--a laboratory evaluation of five low-cost media for their ability to remove metals and phosphorus from artificial stormwater.
Wium-Andersen T, Nielsen AH, Hvitved-Jacobsen T, Kristensen NK, Brix H, Arias C, Vollertsen J.
Water Environ Res. 2012 Jul;84(7):605-16.
PMID:
22876483
[PubMed - in process]
Toxic effects of heavy metals (Cd, Cr and Pb) on seed germination and growth and DPPH-scavenging activity in Brassica rapa var. turnip.
Siddiqui MM, Abbasi BH, Ahmad N, Ali M, Mahmood T.
Toxicol Ind Health. 2012 Aug 7. [Epub ahead of print]
PMID:
22872632
[PubMed - as supplied by publisher]
Efficacy of Er,Cr:YSGG laser with endodontical radial firing tips on the outcome of endodontic treatment: blind randomized controlled clinical trial with six-month evaluation.
Martins MR, Carvalho MF, Vaz IP, Capelas JA, Martins MA, Gutknecht N.
Lasers Med Sci. 2012 Aug 7. [Epub ahead of print]
PMID:
22869158
[PubMed - as supplied by publisher]
Application of Zeeman Graphite Furnace Atomic Absorption Spectrometry with High-Frequency Modulation Polarization for the Direct Determination of Aluminum, Beryllium, Cadmium, Chromium, Mercury, Manganese, Nickel, Lead, and Thallium in Human Blood.
Ivanenko NB, Solovyev ND, Ivanenko AA, Ganeev AA.
Arch Environ Contam Toxicol. 2012 Aug 7. [Epub ahead of print]
PMID:
22868581
[PubMed - as supplied by publisher]
Breast Milk Metal Ion Levels in a Young and Active Patient With a Metal-On-Metal Hip Prosthesis.
Nelis R, de Waal Malefijt J, Gosens T.
J Arthroplasty. 2012 Aug 3. [Epub ahead of print]
PMID:
22868068
[PubMed - as supplied by publisher]
Copolymerization of Cyclohexene Oxide and CO(2) with a Chromium Diamine-bis(phenolate) Catalyst.
Dean RK, Dawe LN, Kozak CM.
Inorg Chem. 2012 Aug 6. [Epub ahead of print]
PMID:
22867113
[PubMed - as supplied by publisher]
Site-Selective Spectroscopy of Garnet Crystals Doped with Chromium Ions.
Orucu H, Ozen G, Di Bartolo B, Collins JM.
J Phys Chem A. 2012 Aug 6. [Epub ahead of print]
PMID:
22867053
[PubMed - as supplied by publisher]
Hierarchical Structures of Carbon Nanotubes and Arrays of Chromium-Capped Silicon Nanopillars: Formation and Electrical Properties.
Koch S, Joshi RK, Noyong M, Timper J, Schneider JJ, Simon U.
Chemistry. 2012 Aug 2. doi: 10.1002/chem.201201170. [Epub ahead of print]
PMID:
22865708
[PubMed - as supplied by publisher]
Pentachlorophenol dechlorination and simultaneous Cr(6+) reduction by Pseudomonas putida SKG-1 MTCC (10510): characterization of PCP dechlorination products, bacterial structure, and functional groups.
Garg SK, Tripathi M, Singh SK, Singh A.
Environ Sci Pollut Res Int. 2012 Aug 5. [Epub ahead of print]
PMID:
22864755
[PubMed - as supplied by publisher]
Chemometric characterization of river water quality.
Kumari M, Tripathi S, Pathak V, Tripathi BD.
Environ Monit Assess. 2012 Aug 4. [Epub ahead of print]
PMID:
22864578
[PubMed - as supplied by publisher]
Migration of eight harmful elements from metal accessories that infants may swallow by mistake.
Isama K, Kawakami T, Nishimura T.
Yakugaku Zasshi. 2012;132(8):959-68.
PMID:
22864356
[PubMed - in process]
Free Article
Performance and metabolic responses of Holstein calves to supplemental chromium in colostrum and milk.
Ghorbani A, Sadri H, Alizadeh AR, Bruckmaier RM.
J Dairy Sci. 2012 Aug 2. [Epub ahead of print]
PMID:
22863099
[PubMed - as supplied by publisher]
DFT study on the mechanism of water-assisted dihydrogen elimination in group 6 octahedral metal hydride complexes.
Sandhya KS, Suresh CH.
Dalton Trans. 2012 Aug 3. [Epub ahead of print]
PMID:
22859021
[PubMed - as supplied by publisher]
Cr(VI) induces the decrease of ATP level and the increase of apoptosis rate mediated by ROS or VDAC1 in L-02 hepatocytes.
Yuan Y, Ming Z, Gong-Hua H, Lan G, Lu D, Peng L, Feng J, Cai-Gao Z.
Environ Toxicol Pharmacol. 2012 Jul 7;34(2):579-587. [Epub ahead of print]
PMID:
22858589
[PubMed - as supplied by publisher]
Regioselective synthesis of fraxinellone-based hydrazone derivatives as insecticidal agents.
Guo Y, Yan YY, Yang C, Yu X, Zhi XY, Xu H.
Bioorg Med Chem Lett. 2012 Jul 21. [Epub ahead of print]
PMID:
22858136
[PubMed - as supplied by publisher]
Association between lung function in school children and exposure to three transition metals from an e-waste recycling area.
Zheng G, Xu X, Li B, Wu K, Yekeen TA, Huo X.
J Expo Sci Environ Epidemiol. 2012 Aug 1. doi: 10.1038/jes.2012.84. [Epub ahead of print]
PMID:
22854517
[PubMed - as supplied by publisher]
Selected Vitamins and Essential Elements in Meat from Semi-Domesticated Reindeer (Rangifer tarandus tarandus L.) in Mid- and Northern Norway: Geographical Variations and Effect of Animal Population Density.
Hassan AA, Sandanger TM, Brustad M.
Nutrients. 2012 Jul;4(7):724-39. Epub 2012 Jul 10.
PMID:
22852060
[PubMed - in process]
Free PMC Article
Effects of hexavalent chromium on reproductive functions of male adult rats.
Rhouma KB, Marouani N, Tebourbi O, Mahjoub S, Yacoubi MT, Sakly M, Benkhalifa M.
Reprod Biol. 2012 Jul;12(2):119-33.
PMID:
22850466
[PubMed - in process]
Free Article
Surface alterations of several dental materials by a novel ultrasonic scaler tip.
Seol HW, Heo SJ, Koak JY, Kim SK, Baek SH, Lee SY.
Int J Oral Maxillofac Implants. 2012 Jul;27(4):801-10.
PMID:
22848881
[PubMed - in process] |
| 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 g.cm-3 at 20 °C |
1907 °C |
2672 °C |
200.pm |
0.061 nm (+3) ; 0.044 nm (+6) |
652.87 kJ.mol-1 |
|
