TUNGSTEN OR WOLFRAM - Tungsten is a steel-gray to tin-white metal. Tungsten and its alloys are used to make filaments for electric lamps and television tubes, as electrical contacts, x-ray targets, heating elements, for metal evaporation components, and for numerous other high temperature applications. Hastelloy, Stellite, high-speed tool steel, and numerous other alloys contain tungsten. Magnesium and calcium tungstenates are used in fluorescent lighting. Tungsten carbide is important in the mining, metalworking, and petroleum industries.

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Tungsten or Wolfram Facts

Chemical & Physical Properties of Tungsten

by Anne Marie Helmenstine, Ph.D. 

Tungsten is a grayish-white transition metal with atomic number 74 and element symbol W. The symbol comes from another name for the element — wolfram.

While the name tungsten is approved by the IUPAC and is used in Nordic countries and those speaking English or French, most European countries use the name wolfram.

Here is a collection of tungsten or wolfram facts, including the element's properties, uses, and sources.

Tungsten or Wolfram Basic Facts

Tungsten Atomic Number: 74

Tungsten Symbol: W

Tungsten Atomic Weight: 183.85

Tungsten Discovery: Juan Jose and Fausto d'Elhuyar purified tungsten in 1783 (Spain), although Peter Woulfe examined the mineral which came to be known as wolframite and determined that it contained a new substance.

Tungsten Electron Configuration: [Xe] 6s² 4f¹⁴ 5d⁴

Word Origin: Swedish tung sten, heavy stone or wolf rahm and spumi lupi, because the ore wolframite interfered with tin smelting and was believed to devour the tin.

Tungsten Isotopes: Natural tungsten consist of five stable isotopes. Twelve unstable isotopes are known.

Tungsten Properties: Tungsten has a melting point of 3410+/-20°C, boiling point of 5660°C, specific gravity of 19.3 (20°C), with a valence of 2, 3, 4, 5, or 6.

Tungsten is a steel-gray to tin-white metal. Impure tungsten metal is quite brittle, although pure tungsten can be cut with a saw, spun, drawn, forged, and extruded.

Tungsten has the highest melting point and the lowest vapor pressure of the metals.

At temperatures exceeding 1650°C, it has the highest tensile strength.

Tungsten oxidizes in air at elevated temperatures, although it generally has excellent corrosion resistance and is minimally attacked by most acids.

Tungsten Uses: The thermal expansion of tungsten is similar to that of borosilicate glass, so the metal is used for glass/metal seals.

Tungsten and its alloys are used to make filaments for electric lamps and television tubes, as electrical contacts, x-ray targets, heating elements, for metal evaporation components, and for numerous other high temperature applications.

Hastelloy, Stellite, high-speed tool steel, and numerous other alloys contain tungsten.

Magnesium and calcium tungstenates are used in fluorescent lighting.

Tungsten carbide is important in the mining, metalworking, and petroleum industries.

Tungsten disulfide is used as a dry high-temperature lubricant.

Tungsten bronze and other tungsten compounds are used in paints.

Tungsten Sources: Tungsten occurs in wolframite, (Fe, Mn)WO₄, scheelite, CaWO₄, ferberite, FeWO₄, and huebnerite, MnWO₄.

Tungsten is produced commercially by reducing tungsten oxide with carbon or hydrogen.

Biological Role: Tungsten is the heaviest element with known biological functionality.

No use in humans or other eukaryotes is known, but the element is used by bacteria and archaea in enzymes, principally as a catalyst.

It functions in much the same ways as the element molybdenum does in other organisms.

When tungsten compounds are introduced to soil, they inhibit earthworm reproduction.

Scientists are studying the use of tetrathiotungstates for use in biological copper chelation.

Tungsten is a rare element, initially thought to be inert and only slightly toxic to humans.

However, now it is known tungsten dust inhalation, skin contact, or ingestion can cause cancer and other negative health effects.

Tungsten or Wolfram Physical Data

Element Classification: Transition Metal

Density (g/cc): 19.3

Melting Point (K): 3680

Boiling Point (K): 5930

Appearance: tough gray to white metal

Atomic Radius (pm): 141

Atomic Volume (cc/mol): 9.53

Covalent Radius (pm): 130

Ionic Radius: 62 (+6e) 70 (+4e)

Specific Heat (@20°C J/g mol): 0.133

Fusion Heat (kJ/mol): (35)

Evaporation Heat (kJ/mol): 824

Debye Temperature (K): 310.00

Pauling Negativity Number: 1.7

First Ionizing Energy (kJ/mol): 769.7

Oxidation States: 6, 5, 4, 3, 2, 0

Lattice Structure: Body-Centered Cubic

Lattice Constant (Å): 3.160

Anne Marie Helmenstine, Ph.D.

Ph.D. in biomedical sciences from the University of Tennessee at Knoxville - Oak Ridge National Laboratory.

Science educator with experience teaching chemistry, biology, astronomy, and physics at the high school, college, and graduate levels.

ThoughtCo and About Education chemistry expert since 2001.

Widely-published graphic artist, responsible for printable periodic tables and other illustrations used in science.

Experience

Anne Helmenstine, Ph.D. has covered chemistry for ThoughtCo and About Education since 2001, and other sciences since 2013. She taught chemistry, biology, astronomy, and physics at the high school, college, and graduate levels. She has worked as a research scientist and also abstracting and indexing diverse scientific literature for the Department of Energy.

In addition to her work as a science writer, Dr. Helmenstine currently serves as a scientific consultant, specializing in problems requiring an interdisciplinary approach. Previously, she worked as a research scientist and college professor. 

Education

Dr. Helmenstine holds a Ph.D. in biomedical sciences from the University of Tennessee at Knoxville and a B.A. in physics and mathematics with a minor in chemistry from Hastings College. In her doctoral work, Dr. Helmenstine developed ultra-sensitive chemical detection and medical diagnostic tests.

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