Discovery of protactinium

Protactinium was identified in 1917 by two groups working independently: the German chemist Otto Hahn and the Austrian physicist Lise Meitner in Berlin, and the British scientists Frederick Soddy and John Cranston. Hahn and Meitner proposed the name protoactinium, later shortened to protactinium, because the element decays into actinium, meaning it is the parent of actinium. A short-lived isotope had already been observed in 1913 by Kasimir Fajans and Oswald Gohring, who called it brevium. Protactinium is a rare, dense, radioactive metal found in tiny quantities in uranium ores, and it is among the most expensive naturally occurring elements to produce. It has no commercial uses, and is used only in scientific research, for instance in dating ocean sediments.

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