Protactinium

Uses

Protactinium has virtually no industrial or commercial applications, since it’s exceedingly rare, difficult to extract safely, and intensely radioactive. Its main relevance is scientific: researchers use it in nuclear physics studies to better understand radioactive decay processes within the actinide series. One genuinely useful application comes from geology and oceanography, where scientists measure the ratio of protactinium-231 to thorium-230 isotopes preserved in layers of deep ocean sediment, a technique that helps date those sediment layers and study how ocean circulation patterns have shifted over thousands of years.

History

Protactinium was first identified in 1913 by chemists Kasimir Fajans and Oswald Helmuth Göhring, who detected a short-lived radioactive isotope of the element and named it “brevium” because of how quickly it decayed away. Several years later, other researchers, including Otto Hahn and Lise Meitner, identified a much longer-lived isotope of the same element, which could be studied far more practically, and the element was renamed protactinium — reflecting that it decays into actinium, so it precedes actinium in the radioactive decay chain. Because it’s so rare and difficult to isolate, protactinium remained one of the least-studied naturally occurring elements for much of the 20th century.