Definition of technetium in US English:



  • The chemical element of atomic number 43, a radioactive metal. Technetium was the first element to be created artificially, in 1937, by bombarding molybdenum with deuterons.

    • ‘All forms of the element technetium are radioactive and have relatively short half-lives.’
    • ‘Some forms of nuclear radiation - such as the beta-emission from radioactive technetium - 99-are particularly difficult to detect underground, partly because the radiation doesn't travel very far.’
    • ‘An isotope of the rare element technetium, denoted Tc, is widely used to form images of the heart, brain, lungs, spleen, and other organs.’
    • ‘In sentinel biopsy, radiolabelled technetium is injected into the tumor or surrounding lung, and a gamma camera is used to detect the nodes that the cancer is most likely to spread to first.’
    • ‘At Sellafield in Cumbria, tests have shown that discharges of the radioactive pollutant technetium pumped into the Irish Sea have spread as far as Scandinavia and have entered the food chain.’


1940s: modern Latin, from Greek tekhnētos ‘artificial’, from tekhnasthai ‘make by art’, from tekhnē ‘art’.