Tungsten also has four "metastable" states, of which the most stable is 179mW (half-life of 6.4 minutes).
When alloyed in small quantities with steel, tungsten greatly increases the hardness of steel.
Naturally occurring tungsten consists of five radioactive isotopes, but they have such long half-lives that they can be considered stable.
When exposed to air, a protective oxide is formed on the surface of the metal, but tungsten can be oxidized more fully at high temperature.
In chemical terms, tungsten forms compounds in which its "oxidation state" ranges between +2 and +6, but the most common is +6.
Tungsten is a chemical element classified as a transition metal.
In World War II, tungsten played an enormous role in background political dealings.
The metatungstate ion exists as a symmetric cluster of twelve tungsten-oxygen octahedra known as the "Keggin" anion.
Aqueous tungstate solutions are noted for the formation of polyoxoanions (anions that contain tungsten and oxygen) under neutral and acidic conditions.
Some useful compounds of tungsten are described below.
Tungsten typically combines with oxygen to form the yellow tungstic oxide (WO3).
World tungsten reserves have been estimated at 7 million t W. It has been suggested that 30 percent of the reserves are wolframite and 70 percent are scheelite ores.
Tungsten was first hypothesized to exist by Peter Woulfe in 1779, when he examined the mineral wolframite and concluded it must contain a new substance.
In 1781, Carl Wilhelm Scheele ascertained that a new acid could be made from tungstenite.
Another factor that controls the tungsten supply is scrap recycling of tungsten, which has been proven to be a very valuable source.
Tungsten is found in the minerals wolframite (iron-manganese tungstate, FeWO4/MnWO4), scheelite (calcium tungstate, CaWO4), ferberite, and hьbnerite.
Tungsten (formerly wolfram) is a chemical element with the symbol W and atomic number 74.
The metal's resistance to high temperatures, as well as the extreme strength of its alloys, made tungsten a very important raw material for the weapons industry.
Calcium and magnesium tungstates are widely used in fluorescent lighting, and tungsten oxides are used in paints and ceramic glazes.
Tungsten(VI) fluoride (WF6), also known as tungsten hexafluoride, is a colorless gas.
Tungsten oxide (or tungstic oxide, WO3) is a yellow compound of tungsten and oxygen, with a melting point of 1473° C. It is synthesized by heating tungsten or other tungsten oxides in excess oxygen.
On average, two alpha decays of 180W occur in one gram of natural tungsten per year.
Photographic images of the Earth from space reveal its awesome beauty, and at the same time highlight the fragility of our common home, often called "spaceship earth."
Tungsten carbide, a compound of tungsten and carbon, is one of the hardest known substances and is the most common material to make milling and turning tools.
The metal is commercially produced by reducing tungsten oxide with hydrogen or carbon.
Tungsten carbide (WC or W2C) is a chemical compound containing tungsten and carbon.