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.
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.
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
trans-Tetra-carbonyl-bis-[tris-(3-fluoro-phen-yl)phosphane]chromium(0).
Norlidah MN, Yazid MY, Shawkataly OB, Rosli MM, Fun HK.
Acta Crystallogr Sect E Struct Rep Online. 2011 Dec 1;67(Pt 12):m1652-m1653. Epub 2011 Nov 2.
PMID:
22199480
[PubMed - as supplied by publisher]
Preparation and characterization of La(III) encapsulated silica gel/chitosan composite and its metal uptake studies.
Gandhi MR, Meenakshi S.
J Hazard Mater. 2011 Nov 28. [Epub ahead of print]
PMID:
22197561
[PubMed - as supplied by publisher]
Electro-migration of heavy metals in an aged electroplating contaminated soil affected by the coexisting hexavalent chromium.
Zhang W, Zhuang L, Tong L, Lo IM, Qiu R.
Chemosphere. 2011 Dec 23. [Epub ahead of print]
PMID:
22197017
[PubMed - as supplied by publisher]
Angular momentum conservation in dipolar energy transfer.
Guo D, Knight TE, McCusker JK.
Science. 2011 Dec 23;334(6063):1684-7.
PMID:
22194572
[PubMed - in process]
Selected Trace Elements in the Sacramento River, California: Occurrence and Distribution.
Taylor HE, Antweiler RC, Roth DA, Alpers CN, Dileanis P.
Arch Environ Contam Toxicol. 2011 Dec 23. [Epub ahead of print]
PMID:
22193863
[PubMed - as supplied by publisher]
Chromium and genomic stability.
Wise SS, Wise JP Sr.
Mutat Res. 2011 Dec 13. [Epub ahead of print]
PMID:
22192535
[PubMed - as supplied by publisher]
A Theoretical Evaluation of Ethylene Insertion into Chromium Alkyl Bonds of Cp-Donor based Olefin Polymerization Catalysts.
Xu R, Klatt G, Enders M, Koeppel H.
J Phys Chem A. 2011 Dec 22. [Epub ahead of print]
PMID:
22191673
[PubMed - as supplied by publisher]
Adsorption of hexavalent chromium from aqueous solution by modified corn stalk: A fixed-bed column study.
Chen S, Yue Q, Gao B, Li Q, Xu X, Fu K.
Bioresour Technol. 2011 Dec 3. [Epub ahead of print]
PMID:
22189077
[PubMed - as supplied by publisher]
Occurrence of Multidrug-Resistant and Toxic-Metal Tolerant Enterococci in Fresh Feces from Urban Pigeons in Brazil.
da Silva VL, Caçador NC, da Silva CD, Fontes CO, Garcia GD, Nicoli JR, Diniz CG.
Microbes Environ. 2011 Dec 22. [Epub ahead of print]
PMID:
22188908
[PubMed - as supplied by publisher]
Revision of a tibial baseplate using a customized oxinium component in a case of suspected metal allergy. A case report.
Van Opstal N, Verheyden F.
Acta Orthop Belg. 2011 Oct;77(5):691-5.
PMID:
22187849
[PubMed - in process]
Retention Strength of Cobalt-Chromium vs Nickel-Chromium Titanium vs CP Titanium in a Cast Framework Association of Removable Partial Overdenture.
Souza JE, Silva NR, Coelho PG, Zavanelli AC, Ferracioli RC, Zavanelli RA.
J Contemp Dent Pract. 2011 May 1;12(3):179-86.
PMID:
22186813
[PubMed - in process]
Metal analysis, phytotoxic, insecticidal and cytotoxic activities of selected medicinal plants of Khyber Pakhtunkhwa.
Khuda F, Iqbal Z, Zakiullah -, Khan A, Nasir F, Muhammad N, Khan JA, Khan MS.
Pak J Pharm Sci. 2012 Jan;25(1):51-58.
PMID:
22186309
[PubMed - as supplied by publisher]
Correlation between metal allergy and treatment outcomes after ankle fracture fixation.
So S, Harris IA, Naylor JM, Adie S, Mittal R.
J Orthop Surg (Hong Kong). 2011 Dec;19(3):309-13.
PMID:
22184160
[PubMed - in process]
Enhancement of the acute phase response to a lipopolysaccharide challenge in steers supplemented with chromium.
Burdick NC, Bernhard BC, Carroll JA, Rathmann RJ, Johnson BJ.
Innate Immun. 2011 Dec 16. [Epub ahead of print]
PMID:
22180563
[PubMed - as supplied by publisher]
Identification and hexavalent chromium reduction characteristics of Pannonibacter phragmitetus.
Shi Y, Chai L, Yang Z, Jing Q, Chen R, Chen Y.
Bioprocess Biosyst Eng. 2011 Dec 18. [Epub ahead of print]
PMID:
22179413
[PubMed - as supplied by publisher]
Exposure to particulate hexavalent chromium exacerbates allergic asthma pathology.
Schneider BC, Constant SL, Patierno SR, Jurjus RA, Ceryak SM.
Toxicol Appl Pharmacol. 2011 Dec 9. [Epub ahead of print]
PMID:
22178736
[PubMed - as supplied by publisher]
Circulating levels of metals are related to carotid atherosclerosis in elderly.
Lind PM, Olsén L, Lind L.
Sci Total Environ. 2011 Dec 15. [Epub ahead of print]
PMID:
22178028
[PubMed - as supplied by publisher]
Highly active nanoscale zero-valent iron (nZVI)-Fe(3)O(4) nanocomposites for the removal of chromium(VI) from aqueous solutions.
Lv X, Xu J, Jiang G, Tang J, Xu X.
J Colloid Interface Sci. 2011 Dec 1. [Epub ahead of print]
PMID:
22177747
[PubMed - as supplied by publisher]
Airborne concentrations of metals and total dust during solid catalyst loading and unloading operations at a petroleum refinery.
Lewis RC, Gaffney SH, Le MH, Unice KM, Paustenbach DJ.
Int J Hyg Environ Health. 2011 Dec 14. [Epub ahead of print]
PMID:
22177528
[PubMed - as supplied by publisher]
Simultaneous Synthesis of Both Rings of Chromenes via a Benzannulation/o-Quinone Methide Formation/Electrocyclization Cascade.
Majumdar N, Korthals KA, Wulff WD.
J Am Chem Soc. 2011 Dec 16. [Epub ahead of print]
PMID:
22176537
[PubMed - as supplied by publisher] |
| 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 |
|
