va·na·di·um /vəˈnediəm/
 釩


 va·na·di·um /vəˈnedɪəm/ 名詞



 Va·na·di·um n.  Chem. A rare element of the nitrogen-phosphorus group, found combined, in vanadates, in certain minerals, and reduced as an infusible, grayish-white metallic powder. It is intermediate between the metals and the non-metals, having both basic and acid properties. Symbol V (or Vd, rarely). Atomic weight 50.94 (C12=12.000).

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 vanadium
      n : a soft silvery white toxic metallic element used in steel
          alloys; it occurs in several complex minerals including
          carnotite and vanadinite [syn: V, atomic number 23]


 vanadium
 Symbol: V
 Atomic number: 23
 Atomic weight: 50.9415
 Soft and ductile, bright white metal. Good resistance to corrosion by
 alkalis, sulphuric and hydrochloric acid. It oxidizes readily about
 933K. There are two naturally occurring isotopes of vanadium, and 5
 radioisotopes, V-49 having the longest half-life at 337 days. Vanadium
 has nuclear applications, the foil is used in cladding titanium to steel,
 and vanadium-gallium tape is used to produce a superconductive magnet.
 Originally discovered by Andres Manuel del Rio of Mexico City in 1801.
 His discovery went unheeded, however, and in 1820, Nils Gabriel Sefstron
 of Sweden rediscovered it. Metallic vanadium was isolated by Henry Enfield
 Roscoe in 1867. The name vanadium comes from Vanadis, a goddess of
 Scandinavian mythology. Silvery-white metallic transition element.
 Vanadium is essential to ascidians. Rats and chickens are also known
 to require it. Metal powder is a fire hazard, and vanadium compounds
 should be considered highly toxic. May cause lung cancer if inhaled.