Mt Meitnerium 109 (278) 9 7 d 109 [Rn] 5f14 6d7 7s2 2 8 18 32 32 15 2 None Unknown 1 30 m 43.3m AlphaEmission TransitionMetal, Metal, Radioactive, Synthetic MITE-ner-i-um Synthetic radioactive metal. It has no significant commercial applications. Obtained by bombarding bismuth-209 with iron-58. N8VR7Qscq4k Meitnerium

In 1900, William Crookes isolated protactinium as an intensely radioactive material from uranium

Protactinium was first identified in 1913 by Kasimir Fajans and Oswald Helmuth Göhring in Germany.

A more stable isotope of protactinium was discovered in 1917 by Otto Hahn and Lise Meitner at the Kaiser Wilhelm Institute in Berlin. From the Greek protos meaning first 109 1982 Peter Armbruster, Gottfried Münzenber and their co-workers. Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany. Named after Lise "Meitner", the Austrian physicist

Protactinium is toxic and highly radioactive

Protactinium is one of the rarest and most expensive naturally occurring elements

Owing to its scarcity, high radioactivity and high toxicity, there are currently no uses for protactinium outside of scientific research.

With the advent of highly sensitive mass spectrometers, an application of ²³¹Pa as a tracer in geology and paleoceanography has become possible.

Protactinium-231 combined with the thorium-230 can be used to date marine sediments.