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Iridium, 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. 

Iridium is a member of the platinum group of metals. It is the most corrosion resistant metal known. It will not react with any acid and can only be attacked by certain molten salts, such as molten sodium chloride. It is alloyed with platinum to produce highly corrosive resistant electrical contacts for spark plugs. Iridium 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

Highly stable low oxidizing metals such as gold, iridiumaluminum and titanium are used in a host of medical applications, such as to create body implants and in regenerative medicine.

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

Iridium is a Block D, Group 9, Period 6 element. The number of electrons in each of Iridium‘s shells is 2, 8, 18, 32, 15, 2 and its electronic configuration is [Xe] 4f14 5d76s2. In its elemental form iridium‘s CAS number is 7439-88-5. The iridium atom has a radius of and it‘s Van der Waals radius is Iridium is only slightly 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) isotopesOrgano-Metallic Iridium compounds are soluble in organic or non-aqueous solvents. SeeAnalytical Services for information on available certified chemical and physical analysis techniques including MS-ICP, X-Ray Diffraction, PSD and Surface Area (BET) analysis. 

Iridium is found as an uncombined element and in iridium-osmium alloys. Iridium was first discovered by Smithson Tennant in 1804.

Abundance. The following table shows the abundance of iridium and each of its naturally occurringisotopes on Earth along with the atomic mass for each isotope.
Isotope Atomic Mass % Abundance on Earth
Ir-191 190.960591 37.3
Ir-193 192.962924 62.7

The following table shows the abundance of Iridium 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 no data 2 ppb
by Atom no data 0.01 ppb

Safety Data and Biological Role. The safety data for iridium 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. Iridiumcompounds have no biological role. 

Ionization Energy. The ionization energy for iridium (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 865.19 kJ mol-1
2nd Ionization Energy - kJ mol-1
3rd Ionization Energy - kJ mol-1

Conductivity. As to iridium‘s electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ?C is 5.3 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 2.2. The thermal conductivity of iridium is 147 W m-1 K-1

Thermal Properties. The melting point and boiling point for iridium are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
Heat of Fusion 26.4 kJ mol-1
Heat of Vaporization 612.1 kJ mol-1
Heat of Atomization 664.34 kJ mol-1

Formula Atomic Number Molecular Weight Electronegativity (Pauling) Density Melting Point Boiling Point Vanderwaals radius Ionic radius Energy of first ionization
Ir 77 192.2 g.mol -1 2.2 22.4 at 20 °C 2450 °C 4527 °C 0.066 nm (+4)) 865.19 kJ.mol-1