23VVanadium

Vanadium is a chemical element with the 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 Rio'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.

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Atomic properties

Standard atomic weight50.9415 ±1·10-4
Atomic mass50.9415 u

Atomic radii

Radius (empirical)134 pm
Radius (calculated)171 pm
Covalent radius153 ±8 pm

Atomic shell

Electron configurationAr 3d3 4s2
Ionization energy(1st) 6.746187 eV
(2nd) 14.634 eV
(3rd) 29.3111 eV
(4th) 46.709 eV
(5th) 65.28165 eV
Shell model
Electrons
k-shell:2
l-shell:8
m-shell:11
n-shell:2

Physical properties

Phasesolid
Density6.11 g·cm−3 (293.1 K)
Molar volume8.32·10-6 m3·mol−1
Speed of sound4,560 m·s−1 (293.1 K)

Temperatures

Melting point2,183 K
Boiling point3,680 K
Liquid range1,497 K
Transition temperature5.4 K

Enthalpies

Melting enthalpy22.8 kJ·mol-1
Enthalpy of vaporization453 kJ·mol-1
Binding energy515 kJ·mol-1

Heat and conductivity

Specific heat capacity489 J·kg−1·K−1
Thermal conductivity31 W·m-1·K-1
Expansion coefficient8.4·10-6 K-1

Hardnesses

Mohs hardness7
Brinell hardness628 NM·m-2
Vickers hardness628 NM·m-2

Elastic properties

Young’s modulus128 GPa
Shear modulus47 GPa
Bulk modulus160 GPa
Poisson’s ratio0.37

Electrical properties

Electrical conductivity5·106 S·m-1
Resistance2·10-7 Ωm

Magnetism

Magnetismparamagnetic
Magnetic susceptibility2.55·10-4 cm3·mol−1 (298 K)

Optical properties

Reflectivity61 %

Chemical properties

Basicityamphoteric
Oxidation state+5, +4 ,+3 ,+2

Electronegativity

Pauling scale1.63
Sanderson scale1.39
Allred-Rochow scale1.45
Ghosh-Gupta scale3.148 eV
Nagle scale1.27
Pearson absolute negativity3.6 eV

Other properties

Natural occurrenceprimordial
Crystal structureBody-centered cubic
Goldschmidt Classificationlithophile
Superconductorwith transition tempperature (solid body, normal pressure)
Price/kg371 ±14 USD

Natural abundances

satellite_alt
Universe
1,000 ppb ≈ 1·1013 M☉
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Sun
400 ppb ≈ 7.95·1011 Mt
destruction
Meteorite
62,000 ppb ≈ 62 g
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Earth’s crust
190,000 ppb ≈ 5.26·106 Mt
water_drop
Oceans
1.5 ppb ≈ 2.05 Gt
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Flowing water
1 ppb ≈ 16 kt
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Human body
30 ppb ≈ 2.1 mg