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Tellurium, 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. 

Tellurium is a p-type semiconductor, and shows greater conductivity in certain directions, depending on alignment of the atoms. It is grown in crystalline form with other elements such as indium telluride. Its conductivity increases slightly with exposure to light. Tellurium improves the machinability of copper and stainless steel, and its addition to lead decreases the corrosive action of sulfuric acid on lead and improves its strength and hardness. Tellurium is used as a basic ingredient in blasting caps, and is added to cast iron for chill control. Tellurium is used in ceramics.Bismuth telluride has been used in thermoelectric devices. Iron 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.

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

Tellurium is a Block P, Group 16, Period 5 element. The number of electrons in each of Tellurium‘s shells is 2, 8, 18, 18, 6 and its electronic configuration is [Kr] 4d10 5s2 5p4. In its elemental form tellurium‘s CAS number is 13494-80-9. The tellurium atom has a radius of and it‘s Van der Waals radius is is very toxic and can cause birth defects.
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 Tellurium 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. 

Tellurium was first discovered by Franz Muller von Reichenstein in 1782. The name Tellurium originates from the Greek word ‘Tellus‘ meaning Earth.

Abundance. The following table shows the abundance of tellurium and each of its naturally occurringisotopes on Earth along with the atomic mass for each isotope.
Isotope Atomic Mass % Abundance on Earth
Te-120 119.90402 0.10
Te-122 121.903047 2.60
Te-123 122.904273 0.91
Te-124 123.902819 4.82
Te-125 124.904425 7.14
Te-126 125.903306 18.95
Te-128 127.904461 31.69
Te-130 129.906223 33.80

The following table shows the abundance of Tellurium 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 9 ppb
by Atom no data 0.09 ppb

Safety Data and Biological Role. The safety data for tellurium 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. Tellurium compounds have no biological role. 

Ionization Energy. The ionization energy for tellurium (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 869.3 kJ mol-1
2nd Ionization Energy 1794.64 kJ mol-1
3rd Ionization Energy 2697.75 kJ mol-1

Conductivity. As to tellurium‘s electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ?C is 436000 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 2.1. The thermal conductivity of tellurium is 2.35 W m-1 K-1. 

Thermal Properties. The melting point and boiling point for tellurium are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
Heat of Fusion 13.5 kJ mol-1
Heat of Vaporization 104.6 kJ mol-1
Heat of Atomization - kJ mol-1

Formula Atomic Number Molecular Weight Electronegativity (Pauling) Density Melting Point Boiling Point Vanderwaals radius Ionic radius Energy of first ionization
Te 52 127.6 g.mol -1 2.1 6.24 at 20 °C 450 °C 1390 °C 0.221 nm (-2) ; 0.089 (+4) 869.30 kJ.mol-1