Technetium was the first element produced artificially rather than found naturally in significant amounts.
Technetium has atomic number 43 and the symbol Tc. In 1937, Carlo Perrier and Emilio Segrè created and identified technetium by bombarding molybdenum with deuterons in a cyclotron. The name comes from the Greek word technetos, meaning “artificial.”
For many years, chemists had searched for an element occupying the gap between molybdenum and ruthenium in the periodic table. Unlike most lighter elements, technetium has no stable isotopes. Tiny natural quantities can arise from uranium fission or radioactive decay, but the element was first obtained through deliberate nuclear transformation.
Technetium-99m is particularly important in nuclear medicine. It emits gamma radiation suitable for imaging and has a short half-life of about six hours, allowing doctors to obtain diagnostic scans while limiting the time it remains in the body. The “m” in technetium-99m means metastable.