Vanadium | |||||||||||||||||||||||||||||||
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Pronunciation | /vəˈneɪdiəm/ | ||||||||||||||||||||||||||||||
Appearance | blue-silver-grey metal | ||||||||||||||||||||||||||||||
Standard atomic weight Ar°(V) | |||||||||||||||||||||||||||||||
Vanadium in the periodic table | |||||||||||||||||||||||||||||||
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Atomic number (Z) | 23 | ||||||||||||||||||||||||||||||
Group | group 5 | ||||||||||||||||||||||||||||||
Period | period 4 | ||||||||||||||||||||||||||||||
Block | d-block | ||||||||||||||||||||||||||||||
Electron configuration | [Ar] 3d3 4s2 | ||||||||||||||||||||||||||||||
Electrons per shell | 2, 8, 11, 2 | ||||||||||||||||||||||||||||||
Physical properties | |||||||||||||||||||||||||||||||
Phase at STP | solid | ||||||||||||||||||||||||||||||
Melting point | 2183 K (1910 °C, 3470 °F) | ||||||||||||||||||||||||||||||
Boiling point | 3680 K (3407 °C, 6165 °F) | ||||||||||||||||||||||||||||||
Density (at 20° C) | 6.099 g/cm3 [3] | ||||||||||||||||||||||||||||||
when liquid (at m.p.) | 5.5 g/cm3 | ||||||||||||||||||||||||||||||
Heat of fusion | 21.5 kJ/mol | ||||||||||||||||||||||||||||||
Heat of vaporization | 444 kJ/mol | ||||||||||||||||||||||||||||||
Molar heat capacity | 24.89 J/(mol·K) | ||||||||||||||||||||||||||||||
Vapor pressure
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Atomic properties | |||||||||||||||||||||||||||||||
Oxidation states | common: +5 −3,? −1,[4] 0,? +1,[4] +2,[4] +3,[4] +4[4] | ||||||||||||||||||||||||||||||
Electronegativity | Pauling scale: 1.63 | ||||||||||||||||||||||||||||||
Ionization energies |
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Atomic radius | empirical: 134 pm | ||||||||||||||||||||||||||||||
Covalent radius | 153±8 pm | ||||||||||||||||||||||||||||||
Spectral lines of vanadium | |||||||||||||||||||||||||||||||
Other properties | |||||||||||||||||||||||||||||||
Natural occurrence | primordial | ||||||||||||||||||||||||||||||
Crystal structure | body-centered cubic (bcc) (cI2) | ||||||||||||||||||||||||||||||
Lattice constant | a = 302.72 pm (at 20 °C)[3] | ||||||||||||||||||||||||||||||
Thermal expansion | 8.77×10−6/K (at 20 °C)[3] | ||||||||||||||||||||||||||||||
Thermal conductivity | 30.7 W/(m⋅K) | ||||||||||||||||||||||||||||||
Electrical resistivity | 197 nΩ⋅m (at 20 °C) | ||||||||||||||||||||||||||||||
Magnetic ordering | paramagnetic | ||||||||||||||||||||||||||||||
Molar magnetic susceptibility | +255.0×10−6 cm3/mol (298 K)[5] | ||||||||||||||||||||||||||||||
Young's modulus | 128 GPa | ||||||||||||||||||||||||||||||
Shear modulus | 47 GPa | ||||||||||||||||||||||||||||||
Bulk modulus | 160 GPa | ||||||||||||||||||||||||||||||
Speed of sound thin rod | 4560 m/s (at 20 °C) | ||||||||||||||||||||||||||||||
Poisson ratio | 0.37 | ||||||||||||||||||||||||||||||
Mohs hardness | 6.7 | ||||||||||||||||||||||||||||||
Vickers hardness | 628–640 MPa | ||||||||||||||||||||||||||||||
Brinell hardness | 600–742 MPa | ||||||||||||||||||||||||||||||
CAS Number | 7440-62-2 | ||||||||||||||||||||||||||||||
History | |||||||||||||||||||||||||||||||
Discovery | Andrés Manuel del Río[6] (1801) | ||||||||||||||||||||||||||||||
First isolation | Henry Enfield Roscoe (1867) | ||||||||||||||||||||||||||||||
Named by | Nils Gabriel Sefström (1830) | ||||||||||||||||||||||||||||||
Isotopes of vanadium | |||||||||||||||||||||||||||||||
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Vanadium is a chemical element; it has symbol V and atomic number 23. It is a hard, silvery-grey, malleable transition metal. The elemental metal is rarely found in nature, but once isolated artificially, the formation of an oxide layer (passivation) somewhat stabilizes the free metal against further oxidation.
Spanish-Mexican scientist Andrés Manuel del Río discovered compounds of vanadium in 1801 by analyzing a new lead-bearing mineral he called "brown lead". Though he initially presumed its qualities were due to the presence of a new element, he was later erroneously convinced by French chemist Hippolyte Victor Collet-Descotils that the element was just chromium. Then in 1830, Nils Gabriel Sefström generated chlorides of vanadium, thus proving there was a new element, and named it "vanadium" after the Scandinavian goddess of beauty and fertility, Vanadís (Freyja). The name was based on the wide range of colors found in vanadium compounds. Del Río's lead mineral was ultimately named vanadinite for its vanadium content. In 1867, Henry Enfield Roscoe obtained the pure element.
Vanadium occurs naturally in about 65 minerals and fossil fuel deposits. It is produced in China and Russia from steel smelter slag. Other countries produce it either from magnetite directly, flue dust of heavy oil, or as a byproduct of uranium mining. It is mainly used to produce specialty steel alloys such as high-speed tool steels, and some aluminium alloys. The most important industrial vanadium compound, vanadium pentoxide, is used as a catalyst for the production of sulfuric acid. The vanadium redox battery for energy storage may be an important application in the future.
Large amounts of vanadium ions are found in a few organisms, possibly as a toxin. The oxide and some other salts of vanadium have moderate toxicity. Particularly in the ocean, vanadium is used by some life forms as an active center of enzymes, such as the vanadium bromoperoxidase of some ocean algae.