W Keyring 20x30 mm.

<div>   </div> <div> <strong> Atomic number <span class = "Apple-tab-span" style = "white-space: pre"> </span>       74 </strong> </div> <div> <strong> Atomic mass <span class = "Apple-tab-span" style = "white-space: pre"> </span>         183.85 </strong> </div> <div> <strong> Density, kg / m? <span class = "Apple-tab-span" style = "white-space: pre"> </span>       19300 </strong> </div> <div> <strong> Temperature </strong></div> <div> <strong> melting, ° С <span class = "Apple-tab-span" style = " white-space: pre "> </span>           3410 </strong> </div> <div>   </div> <div> Tungsten is a hard shiny silver-gray transition metal. In 1781, the famous Swedish chemist Scheele, treating the scheelite mineral with nitric acid, obtained a yellow “heavy stone” (tungsten trioxide). In 1783, the Spanish chemists Eluard brothers reported on obtaining from the Saxon mineral wolframite both a yellow oxide of a new metal soluble in ammonia, and the metal itself. The refractoriness and plasticity of tungsten make it indispensable for filaments in lighting fixtures, as well as in picture tubes and other vacuum tubes. </div> <div>   </div>