Sulfur is a crucial element for all life and serves as both fuels and respiratory (oxygen-replacing) materials for simple organisms. In nature, sulfur can be found in hot springs, meteorites, volcanoes, and as galena, gypsum, Epsom salts, and barite. Sulfur, when organically bonded, is a component of all proteins, as the amino acids methionine and cysteine. In organic form, Sulfur is present in the vitamins thiamine and biotin. Sulfur is also a vital part of many enzymes and also in antioxidant molecules like glutathione and thioredoxin.Sulfur is available as compounds with purities from 99% to 99.9999% (ACS grade to ultra-high purity). Sulfur facts, including appearance, CAS #, and molecular formula and safety data, research and properties areavailable 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.
Sulfur has been known since ancient times but was not accepted as an element until 1777. Antoine Lavoisier helped to convince the scientific commuity that sulfus is an element and not a compound.
Abundance. The following table shows the abundance of sulfur and each of its naturally occurringisotopes on Earth along with the atomic mass for each isotope.
The following table shows the abundance of Sulfur present in the human body and in the universe scaled to parts per billion (ppb) by weight and by atom:
Safety Data and Biological Role. The safety data for sulfur 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. Carboncompounds play a key biological role in all life and is present by definition in all organic compounds. Ionization Energy. The ionization energy for sulfur (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:
Conductivity. As to sulfur‘s electrical and thermal conductivity, the electrical conductivity measured as to electrical resistivity @ 20 ?C is 2×1015 μΩcm and its electronegativities (or its ability to draw electrons relative to other elements) is 2.58. The thermal conductivity of carbon is 0.205W m-1 K-1. Thermal Properties. The melting point and boiling point for sulfur are stated below. The following chart sets forth the heat of fusion, heat of vaporization and heat of atomization.
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Formula | Atomic Number | Molecular Weight | Electronegativity (Pauling) | Density | Melting Point | Boiling Point | Vanderwaals radius | Ionic radius | Energy of first ionization |
S | 16 | 32.065 (5) g.mol-1 | 2.58 | 2 g.cm-3 at 20 °C | 115.2°C | 444.7°C | 180.pm | 30 (+6e) 184 (-2e) | 999.0 kJ.mol-1 |