- Tungsten (W), also known as wolfram, is a transition metal with atomic number 74, located in Group 6 of the periodic table.
- Its electron configuration is [Xe] 4f¹⁴ 5d⁴ 6s², giving it six valence electrons. Each atom of tungsten contains seventy-four protons, seventy-four electrons, and around one hundred and ten neutrons in its most common isotope.
- Naturally occurring tungsten consists of five stable isotopes, the most abundant being tungsten-184 (¹⁸⁴W).
- The element was first identified in 1781 by Carl Wilhelm Scheele, who recognized it in the mineral scheelite (CaWO₄). In 1783, Spanish brothers Juan José and Fausto Elhuyar successfully isolated tungsten metal by reducing tungsten trioxide (WO₃) with charcoal. Its name derives from the Swedish words tung sten, meaning “heavy stone,” reflecting its density. The alternative name wolfram is still widely used in Europe, particularly in relation to its chemical symbol, W.
- Physically, tungsten is a grayish-white metal renowned for its exceptional properties. It is the heaviest element in the 4d and 5d transition metal series, with a density of 19.25 g/cm³, nearly equal to gold and uranium. Tungsten has the highest melting point of all metals—3,422 °C (6,192 °F)—and one of the highest boiling points, 5,555 °C (10,031 °F). It is also extremely hard, strong, and resistant to wear.
- Chemically, tungsten is relatively inert, showing strong resistance to corrosion and oxidation at normal temperatures. At high temperatures, however, it reacts with oxygen to form tungsten trioxide (WO₃). It also forms halides such as tungsten hexafluoride (WF₆), which is used in semiconductor manufacturing. Tungsten typically exhibits oxidation states ranging from +2 to +6, with +6 being the most stable and common.
- Tungsten has a wide array of applications due to its unique physical characteristics. One of its most famous uses is in filaments for incandescent light bulbs, where its high melting point prevents melting at operating temperatures. It is also used in electrodes, heating elements, and radiation shielding. Tungsten carbide (WC), an extremely hard compound, is widely used in cutting tools, mining equipment, and industrial machinery. In aerospace and military applications, tungsten is valued for its density and strength, being used in armor-piercing projectiles, counterweights, and superalloys for turbine blades. Additionally, tungsten’s compounds are employed in electronics, catalysts, and chemical processes.
- Biologically, tungsten is not essential for humans but does play a role in the metabolism of some bacteria and archaea. In trace amounts, tungsten compounds are not highly toxic, but exposure to large amounts of tungsten dust or soluble compounds can cause respiratory and kidney problems.
- Environmentally, tungsten is relatively rare in Earth’s crust, occurring at about 1.25 parts per million. It is mainly found in minerals such as scheelite (CaWO₄) and wolframite ((Fe,Mn)WO₄). The largest producers of tungsten today are China, Russia, Portugal, and Austria. While tungsten mining is generally less environmentally damaging than some other metals, its intensive use in military and industrial applications raises sustainability concerns.
