technetium

[tek-nee-shee-uhm, -shuhm]
noun
Chemistry. an element of the manganese family, not found in nature, but obtained in the fission of uranium or by the bombardment of molybdenum. Symbol: Tc; atomic weight: 99; atomic number: 43; specific gravity: 11.5.

Origin:
1945–50; < Greek technēt(ós) artificial (literally, made, verbid of technâsthai; see techno-) + -ium

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World English Dictionary
technetium (tɛkˈniːʃɪəm)
 
n
a silvery-grey metallic element, artificially produced by bombardment of molybdenum by deuterons: used to inhibit corrosion in steel. The radioisotope technetium-99m, with a half-life of six hours, is used in radiotherapy. Symbol: Tc; atomic no: 43; half-life of most stable isotope, 97Tc: 2.6 × 106 years; valency: 0, 2, 4, 5, 6, or 7; relative density: 11.50 (calculated); melting pt: 2204°C; boiling pt: 4265°C
 
[C20: New Latin, from Greek tekhnētos manmade, from tekhnasthai to devise artificially, from tekhnē skill]

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Medical Dictionary

technetium tech·ne·ti·um (těk-nē'shē-əm, -shəm)
n.
Symbol Tc
A radioactive metal, the first synthetically produced element, used as a tracer and to inhibit corrosion in steel. Atomic number 43; melting point 2,200°C; specific gravity 11.50; valence 0, 2, 4, 5, 6, 7.

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Science Dictionary
technetium   (těk-nē'shē-əm)  Pronunciation Key 
Symbol Tc
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. See Periodic Table.
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