Technetium definitions

tĕk-nē'shē-əm, -shəm
A silvery-gray radioactive metal, the first synthetically produced element, having isotopes with masses ranging from 85 to 118 and half-lives up to 4.2 million years. It is principally used as a tracer in a variety of medical applications. It is a remarkable inhibitor of corrosion in steel, but this use is limited because of radioactivity hazards. Atomic number 43; melting point 2,157°C; boiling point 4,265°C; specific gravity 11.50 (calculated); valence 0, 2, 4, 5, 6, 7.
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A silver-gray, metallic chemical element obtained by the irradiation of molybdenum with deuterons and in the fission of uranium: it does not exist in nature and all its isotopes are radioactive: it is a superconductor, an inhibitor of metal corrosion, and a medical tracer: symbol, Tc; at. no. 43
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A silvery-gray, radioactive metallic element. It was the first element to be artificially made, and it is produced naturally in extremely small amounts during the radioactive decay of uranium. Technetium is used to remove corrosion from steel. Its longest-lived isotope is Tc 98 with a half-life of 4,200,000 years. Atomic number 43; melting point 2,200°C; specific gravity 11.50; valence 0, 2, 4, 5, 6, 7.
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A metallic chemical element (symbol Tc) with an atomic number of 43.
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Origin of technetium

From Greek tekhnētos artificial from tekhnāsthai to make by art from tekhnē art technical