| 单词 | technetium |
| 释义 | Word Frequency technetium(tɛkˈniːʃɪəm) noun 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 Word origin C20: New Latin, from Greek tekhnētos manmade, from tekhnasthai to devise artificially, from tekhnē skill |
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