technetium (redirected from 99m)

tech·ne·ti·um  (tk-nsh-m, -shm)

n. Symbol Tc

A silvery-gray radioactive metal, the first synthetically produced element, having 14 isotopes with masses ranging from 92 to 105 and half-lives up to 4.2 × 10⁶ years. It is used as a tracer and to eliminate corrosion in steel. Atomic number 43; melting point 2,200°C; specific gravity 11.50; valence 0, 2, 4, 5, 6, 7. See Table at element.

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[From Greek tekhntos, artificial, from tekhnsthai, to make by art, from tekhn, art; see technical.]

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technetium [tɛkˈniːʃɪəm]

n

(Chemistry / Elements & Compounds) 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

[New Latin, from Greek tekhnētos manmade, from tekhnasthai to devise artificially, from tekhnē skill]

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technetium  (tk-nsh-m)

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.

Thesaurus

Noun

1.

technetium - a crystalline metallic element not found in nature; occurs as one of the fission products of uranium atomic number 43, Tc metal, metallic element - any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.

Translations

technetium [tekˈniːʃɪəm] N → tecnetio m