A metallic element. The atomic number is 74 and the atomic weight is 183.84. Steel is gray or silvery white, with high hardness and high melting point, and is not corroded by air at room temperature; It is mainly used to manufacture filament, high-speed cutting alloy steel and superhard die, and also used in optical instruments and chemical instruments. China is the largest tungsten reserve country in the world. Tungsten is widely used, involving mining, metallurgy, machinery, construction, transportation, electronics, chemical industry, light industry, textile, military industry, aerospace, science and technology and various industrial fields.

Introduction of tungsten:

This is a metallic element. The chemical element symbol of tungsten is W, the atomic number is 74, the relative atomic mass is 183.85, the atomic radius is 137 picometers, and the density is 19.35g/cm3, which belongs to VIB family of the sixth period (the second longest period) in the periodic table. Tungsten is mainly a hexavalent cation in nature, and its ionic radius is 0.68× 10- 10m. Because of the small ionic radius, high electricity price and strong polarization ability of W6+, it is easy to form complex anions, so tungsten mainly exists in the form of complex anion [WO4]2-, which combines with cations such as Fe2+, Mn2+ and Ca2+ in the solution to form wolframite or scheelite precipitate. Tungsten is a silvery white lustrous metal after smelting, with high melting point, high hardness, low vapor pressure, low evaporation rate and relatively stable chemical properties.