Tungsten General Electric's attempt to patent it, overturning granted in 1913 to William D. Coolidge. Tungsten Tungsten, or wolfram, is a chemical element with symbol W and atomic number 74. The name "tungsten" comes from the former Swedish name for the tungstate mineral "scheelite", "tung sten" or "heavy stone". Tungsten is a rare metal found naturally on Earth almost exclusively combined with other elements in chemical compounds rather than alone. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include wolframite and scheelite. The free element is remarkable for its
Melting point "ΔH" are respectively the temperature at the melting point, change of entropy of melting and the change of enthalpy of melting. The melting point is sensitive to extremely large changes in pressure, but generally this sensitivity is orders of magnitude less than that for the boiling point, because the solid-liquid transition represents only a small change in volume. If, as observed in most cases, a substance is more dense in the solid than in the liquid state, the melting point will increase with increases in pressure. Otherwise the reverse behavior occurs. Notably, this is the case of water, as illustrated