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tantalum |
3 definitions found From Webster's Revised Unabridged Dictionary (1913) [web1913]: Tantalum \Tan"ta*lum\, n. [NL. So named on account of the perplexity and difficulty encounterd by its discoverer Ekeberg in isolating it See {Tantalus}.] (Chem.) A rare nonmetallic element found in certain minerals, as tantalite, samarskite, and fergusonite, and isolated as a dark powder which becomes steel-gray by burnishing. Symbol Ta Atomic weight 182.0. Formerly called also {tantalium}. From WordNet r 1.6 [wn]: tantalum n : a hard gray lustrous metallic element that is highly corrosion-resistant; occurs in niobite and fergusonite and tantalite [syn: {Ta}, {atomic number 73}] From Elements database 20001107 [elements]: tantalum Symbol: Ta Atomic number: 73 Atomic weight: 180.948 Heavy blue-grey metallic transition element. Ta-181 is a stable isotope, and Ta-180 is a radioactive isotope, with a half-life in excess of 10^7 years. Used in surgery as it is unreactive. Forms a passive oxide layer in air. Identified in 1802 by Ekeberg and isolated in 1820 by Jons J. Berzelius.
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