Tungsten

Tungsten is a heavy, gray metal with the highest melting point of any metal, about 3,422 °C, and it is about as dense as gold. The brothers Juan José and Fausto Elhuyar first isolated it in Spain in 1783. Its symbol, W, comes from wolfram, after the ore wolframite. Most is mined in China.

Inside a chip, each transistor must be connected to the copper wiring stacked above it through holes only a few tens of nanometers wide. Tungsten, deposited from tungsten hexafluoride gas (WF₆), fills them evenly with solid plugs that survive high heat. Elsewhere, tungsten carbide makes drill bits and cutting tools, and tungsten wire was the glowing filament of the classic light bulb.