A radioactive metallic transition element; a.n. 43; m.p. 2172°C; b.p. 4877°C. The element can be detected in certain stars and is present in the fission products of uranium. It was first made in 1937 by Carlo Perrier (1886–1948) and Emilio Segrè (1905–89), who bombarded molybdenum with deuterons to give technetium–97. The most stable isotope is technetium–99 (half-life 2.6 × 106 years); this is used to some extent in labelling for medical diagnosis. There are sixteen known isotopes. Chemically, the metal has properties intermediate between manganese and rhenium.
https://www.webelements.com/technetium/ Information from the WebElements site