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 Tungsten is the chemical element with atomic number 74, symbol W (from German Wolfram). Its name in French comes from the Swedish tung ("heavy") and sten ("stone") and therefore means "heavy stone".

Tungsten is found in many minerals such as wolframite and scheelite. The simple tungsten body is a very hard and heavy gray-white steel transition metal. In its pure form, it is mainly used in electrical applications (filaments of incandescent lamps), but in the form of compounds or alloys, it has many applications, such as the production of tools requiring high hardness.

Tungsten has 35 known isotopes, with a mass number varying between 158 and 192, as well as 11 nuclear isomers. Among these isotopes, four are stable, 182W, 183W, 184W and 186W, and they constitute with 180W, a very long-lived radioisotope (half-life of 1.8 ¡Á 1018 years), all of natural tungsten, in proportions varying from 14 to 30% (0.12% for 180W). Like all elements heavier than zirconium, tungsten is theoretically unstable, and all of its stable isotopes are suspected of being weakly radioactive, disintegrating by ¦Á emission into isotopes of the corresponding hafnium. Tungsten is assigned a standard atomic mass of 183.84 (1) u.



  

 

   magnesium    bismuth   manganese   chromium    cobalt    titanium

    Tungsten    vanadium   niobium   indium     molybdenum     antimony

      rhenium    germanium    zirconium     cadmium     hafnium

 

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