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Protactinium (Pa): Actinides

Protactinium (Pa)

What is Protactinium?

Protactinium is one of the rarest elements on Earth. It is formed when uranium and other radioactive elements break down. For many years, the only supply of protactinium of any size was kept in Great Britain. The British government had spent $500,000 to extract 125 grams (about four ounces) of the element from 60 tonnes (60 tons) of radioactive waste. Relatively little is known about the properties of the element, and it has no commercial uses.

Protactinium belongs in the actinides series in the periodic table. The periodic table is a chart that shows how chemical elements are related to one another.  

The amount of protactinium in the Earth's crust is too small to estimate accurately. Its most common ore, pitchblende, contains about 0.1 part per million of protactinium.  Continue reading from Chemistry Explained

The History

The existence of an element between thorium and uranium was predicted by Dmitri Mendeleev in 1871. In 1900, William Crookes isolated protactinium as a radioactive material from uranium, but he could not identify the material.  Protactinium was first identified in 1913, when Kasimir Fajans and O. H. Göhring encountered short-lived isotope protactinium-234m, with a half-life of about 1.17 minutes, during their studies of the decay chain of uranium-238. They gave the new element the name brevium (Latin brevis, meaning brief or short). The name was changed to protoactinium in 1918, when two groups of scientists—Otto Hahn and Lise Meitner of Germany and Frederick Soddy and John Cranston of the UK—independently discovered Pa-231. The name was shortened to protactinium in 1949. Continue reading from New World Encyclopedia

Protactinium Facts

Protactinium is harmful due to its radioactivity and is also toxic. Protactinium is a very rare shiny, silvery, highly radioactive metal that tarnishes slowly in air to the oxide. Almost all naturally occurring protactinium is the 231 isotope. It emits alpha radiation and is produced through the decay of uranium-235. Protactinium is one of the rarest and most expensive naturally occurring elements.  Continue reading from Chemicool

Chart of Elemental Properties for Protactinium

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