The chemical element first produced artificially is technetium, whose symbol is Tc.
Emilio Segrè and Carlo Perrier created technetium in 1937 by bombarding molybdenum with deuterons at the Berkeley cyclotron. The name comes from the Greek technetos, meaning “artificial,” reflecting its historic status as the first element made rather than discovered in nature.
Technetium has atomic number 43 and no stable isotopes. Minute natural traces can form in uranium ores, but most technetium used by people is produced in nuclear reactors or particle accelerators.
Technetium-99m is especially important in nuclear medicine. It emits gamma radiation suitable for imaging and has a short half-life of about six hours, allowing doctors to observe organs while limiting how long the isotope remains radioactive. It is distinct from technetium-99, a much longer-lived isotope.