technetium(redirected from 99m)
Also found in: Thesaurus, Medical, Encyclopedia.
n. Symbol Tc
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. See Periodic Table.
[From Greek tekhnētos, artificial, from tekhnāsthai, to make by art, from tekhnē, art; see technical.]
(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
[C20: New Latin, from Greek tekhnētos manmade, from tekhnasthai to devise artificially, from tekhnē skill]
tech•ne•ti•um(tɛkˈni ʃi əm, -ʃəm)
a synthetic element obtained in the fission of uranium or by the bombardment of molybdenum. Symbol: Tc; at. wt.: 99; at. no.: 43; sp. gr.: 11.5.
[1947; < Greek technēt(ós) artificial, literally, made, v. adj. of technâsthai, derivative of téchnē art, craft]
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. Atomic number 43. See Periodic Table.
Switch to new thesaurus
|Noun||1.||technetium - a crystalline metallic element not found in nature; occurs as one of the fission products of uranium|
technetium[tekˈniːʃɪəm] N → tecnetio m
n. tecnecio 99m., radioisótopo que emite rayos gamma, de uso frecuente en medicina nuclear.