Wednesday, February 11, 2004


�(Tc), � chemical element, synthetic radioactive metal of Group VIIb of the periodic table, the first element to be artificially produced. The isotope technetium-97 (2,600,000-year half-life) was discovered (1937) by the Italian mineralogist Carlo Perrier and the Italian-born American physicist Emilio Segr� in a sample of molybdenum that had been bombarded by deuterons in the Berkeley (California)


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