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An unstable radioactive element of the Magnesium family. Technetium was the first artificially produced element in 1927. Carlo Perrier and Emilio Segre made technetium by the deuteron bombardment of Molybdenum. Naturally occurring technetium is rare on earth, but in 1952, it was detected in the emission of S-type stars. It is used to increase corrosion resistance of Steel and, in medicine, as a radioactive imaging agent for the liver.

Synonyms and Related Terms

Tc; masurium; technétium (Fr.); tecnezio (It.); tecnécio (Port.); tecnecio (Esp.); Teknetium (Sven.); Technetium (Deut., Ned.); technet (Pol.)

Physical and Chemical Properties

Dissolves in nitric acid, aqua regia, concentrated sulfuric acid

Composition Tc (atomic no. 43)
CAS 7440-26-8
Melting Point 2200 C
Density 11.5
Molecular Weight atomic wt = 98.9062

Resources and Citations

  • Chemical & Engineering News, American Chemical Society, Washington DC, 81 (36) , Sept. 8, 2003 Comment: John T. Armstrong, p. 110
  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 9286
  • Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
  • Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
  • The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998