Chemistry: Tungsten
Tungsten filament in halogen lamp.
Color: greyish white, lustrous
Tungsten has the highest melting point, which is 3695 K (3422 °C, 6192 °F), and lowest vapour pressure of all metals, and at temperatures over 1650°C has the highest tensile strength.
The name Tungsten comes from the Swedish tung sten, meaning "heavy stone".
In its raw form, tungsten is a steel-gray metal that is often brittle and hard to work. But, if pure, it can be worked easily. Elemental tungsten resists attack by oxygen, acids, and alkalis.
Tungsten is found in the minerals wolframite, scheelite, ferberite and hübnerite. These are mined and used to produce about 37,400 tons of tungsten concentrates per year in 2000.Over 75% of this production came from China, while most of the remaining production is done in Austria, Bolivia, Portugal, and Russia.
Tungsten has many uses some are:
- light bulb filaments
- cathode-ray tube filaments
- vacuum tube filaments
- heating elements
- rocket engine nozzles
- electrodes
- electron microscopes
- plastic composite filler
- glass-to-metal seals
- turbine blades
- darts
- weights for fishing lures
- cannon shells (to create supersonic shrapnel)
- grenades (to create supersonic shrapnel)
- missiles (to create supersonic shrapnel)
- wear-resistant abrasives
- cutters and knives for drills, circular saws, milling and turning tools.
Sources:
Wikipedia
webelements.com
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