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Thorium, 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. 

Thorium is a lanthanide (rare earth) material with potential nuclear power applications. Thorium 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 presently used as a tungsten coating in electronic parts due to its high emission factor. Thorium in the form of its fluoride and oxide is used in advanced optic applications for its high refractive index. It is also used in several other high temperature glass applications, such as in the mantle of lamps and to produce crystal growth crucibles and ampules. The name Thorium originates from the Scandinavian god, Thor, the Norse god of war and thunder.

Thorium 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 High Purity (99.999%) Thorium Oxide (ThO2) Powderas 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. Thorium is available in soluble forms including chlorides, nitrates and acetates. These compounds are also manufactured as solutions at specified stoichiometries. 

Thorium is a Block F, Group 3, Period 7 element. The number of electrons in each of Thorium‘s shells is 2, 8, 18, 32, 18, 10, 2 and its electronic configuration is [Rn] 6d2 7s2. In its elemental form thorium‘s CAS number is 7440-29-1. The thorium atom has a radius of and it‘s Van der Waals radius is Thorium is radioactive and can collect in bones which may cause bone cancer several years after exposure. Breathing in substantial amounts of thorium may be lethal. 

High Purity (99.999%) Thorium (Th) Sputtering TargetAll 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 Thorium 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. 

Thorium, first discovered by Jons Berzelius in 1828, is found in small amounts in most rocks and soils.

Abundance. The following table shows the abundance of thorium and each of its naturally occurringisotopes on Earth along with the atomic mass for each isotope.

Isotope Atomic Mass % Abundance on Earth
Th-229 229.031755 *
Th-230 232.038050 100

The following table shows the abundance of Thorium 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 0.4 ppb
by Atom no data 0.002 ppb

Safety Data and Biological Role. The safety data for thorium 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. Thorium compounds have no biological role. 

Ionization Energy. The ionization energy for thorium (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 608.51 kJ mol-1
2nd Ionization Energy 1109.59 kJ mol-1
3rd Ionization Energy 1929.72 kJ mol-1

Conductivity. As to thorium‘s electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ?C is 13 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 1.3. The thermal conductivity of thorium is 54 W m-1 K-1. 

Thermal Properties. The melting point and boiling point for thorium are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
Heat of Fusion 19.2 kJ mol-1
Heat of Vaporization 513.67 kJ mol-1
Heat of Atomization 598.65 kJ mol-1

Formula Atomic Number Molecular Weight Electronegativity (Pauling) Density Melting Point Boiling Point Vanderwaals radius Ionic radius Energy of first ionization
Th 90 232.04 g.mol-1 1.3 11.72 at 20 °C 1750 °C 4790 °C 0.110 nm (+4) 608.51 kJ.mol-1