Tungsten or Wolfram - Chemical Physical Properties

Tungsten or Wolfram - Chemical Physical Properties Tungsten is a grayish-white transition metal with atomic number 74 and element symbol W. The symbol comes from another name for the element- wolfram. While the name tungsten is approved by the IUPAC and is used in Nordic countries and those speaking English or French, most European countries use the name wolfram. Here is a collection of tungsten or wolfram facts, including the elements properties, uses, and sources. Tungsten or Wolfram  Basic Facts Tungsten Atomic Number: 74 Tungsten Symbol: W Tungsten Atomic Weight: 183.85 Tungsten Discovery: Juan Jose and Fausto dElhuyar purified tungsten in 1783 (Spain), although Peter Woulfe examined the mineral which came to be known as wolframite and determined that it contained a new substance. Tungsten Electron Configuration: [Xe] 6s2 4f14 5d4 Word Origin: Swedish tung sten, heavy stone or wolf rahm and spumi lupi, because the ore wolframite interfered with tin smelting and was believed to devour the tin. Tungsten Isotopes: Natural tungsten consist of five stable isotopes. Twelve unstable isotopes are known. Tungsten Properties: Tungsten has a melting point of 3410/-20 °C, boiling point of 5660 °C, specific gravity of 19.3 (20 °C), with a valence of 2, 3, 4, 5, or 6. Tungsten is a steel-gray to tin-white metal. Impure tungsten metal is quite brittle, although pure tungsten can be cut with a saw, spun, drawn, forged, and extruded. Tungsten has the highest melting point and the lowest vapor pressure of the metals. At temperatures exceeding 1650 °C, it has the highest tensile strength. Tungsten oxidizes in air at elevated temperatures, although it generally has excellent corrosion resistance and is minimally attacked by most acids. Tungsten Uses: The thermal expansion of tungsten is similar to that of borosilicate glass, so the metal is used for glass/metal seals. Tungsten and its alloys are used to make filaments for electric lamps and television tubes, as electrical contacts, x-ray targets, heating elements, for metal evaporation components, and for numerous other high temperature applications. Hastelloy, Stellite, high-speed tool steel, and numerous other alloys contain tungsten. Magnesium and calcium tungstenates are used in fluorescent lighting. Tungsten carbide is important in the mining, metalworking, and petroleum industries. Tungsten disulfide is used as a dry high-temperature lubricant. Tungsten bronze and other tungsten compounds are used in paints. Tungsten Sources: Tungsten occurs in wolframite, (Fe, Mn)WO4, scheelite, CaWO4, ferberite, FeWO4, and huebnerite, MnWO4. Tungsten is produced commercially by reducing tungsten oxide with carbon or hydrogen. Biological Role: Tungsten is the heaviest element with known biological functionality. No use in humans or other eukaryotes is known, but the element is used by bacteria and archaea in enzymes, principally as a catalyst. It functions in much the same ways as the element molybdenum does in other organisms. When tungsten compounds are introduced to soil, they inhibit earthworm reproduction. Scientists are studying the use of tetrathiotungstates for use in biological copper chelation. Tungsten is a rare element, initially thought to be inert and only slightly toxic to humans. However, now it is known tungsten dust inhalation, skin contact, or ingestion can cause cancer and other negative health effects. Tungsten or Wolfram Physical Data Element Classification: Transition Metal Density (g/cc): 19.3 Melting Point (K): 3680 Boiling Point (K): 5930 Appearance: tough gray to white metal Atomic Radius (pm): 141 Atomic Volume (cc/mol): 9.53 Covalent Radius (pm): 130 Ionic Radius: 62 (6e) 70 (4e) Specific Heat (20 °C J/g mol): 0.133 Fusion Heat (kJ/mol): (35) Evaporation Heat (kJ/mol): 824 Debye Temperature (K): 310.00 Pauling Negativity Number: 1.7 First Ionizing Energy (kJ/mol): 769.7 Oxidation States: 6, 5, 4, 3, 2, 0 Lattice Structure: Body-Centered Cubic Lattice Constant (Ã…): 3.160 Sources Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. ISBN 978-1-4200-9084-0.Hille, Russ (2002). Molybdenum and tungsten in biology. Trends in Biochemical Sciences. 27 (7): 360–367. doi:10.1016/S0968-0004(02)02107-2Lassner, Erik; Schubert, Wolf-Dieter (1999). Tungsten: properties, chemistry, technology of the element, alloys, and chemical compounds. Springer. ISBN 978-0-306-45053-2.Stwertka, Albert (2002). A Guide to the Elements (2nd ed.). New York: Oxford University Press. ISBN 978-0-19-515026-1.Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. ISBN 0-8493-0464-4.

5 Reasons to Go Into an Allied Healthcare Career

5 Reasons to Go Into an Allied Healthcare Career maybe you want to work in healthcare, but you don’t have the option to go through intensive training or certification. there are many well-paying, exciting fields that don’t require this kind of preparation, but which can still be incredibly rewarding. there are jobs you can afford to pursue, even without a traditional college education. that being said, here are 5 reasons you should go into an allied healthcare career.1. flexibilitywhile an advanced degree can only give you an extra boost, it is not required by any means. allied healthcare positions, like being a technician or technologist, can give you great quality training- fast. you can work in all types of settings, all around the world. though each state and institution might have slightly different requirements, you’ll find it easy to move around and be eligible in different parts of the country when you need a change of scenery.2. satisfactionyou could do much worse than helping people, working side by s ide with other committed folks like you, making the world a safer and healthier place. these jobs really can make a difference in people’s lives and can be immensely fulfilling.3. securitythis field continues to grow at rates of almost 25% per year. with lower requirements and high advancement potential, these jobs provide great salaries and good staying power across a wide range of fields.4. competitionstarting salaries in this field rival positions requiring much more experience in other fields. and the benefits tend to be comparatively very generous.5. military advantagesif you have any interest in one day pursuing a career in the military, then working in the allied healthcare professions can be incredibly helpful. there are great benefits to a military career, including helping people, serving your country, and good, low-cost insurance. if you want to get working sooner rather than later, consider this route to your healthcare career!interested? apply here