Protactinium is a chemical element; it has symbol Pa and atomic number 91. It is a dense, radioactive, silvery-gray actinide metal which readily reacts with oxygen, water vapor, and inorganic acids.

Predicted by Dimitri Mandeleev in 1871, protactinium was first identified in 1913 by Kasimir Fajans and Oswald Helmuth Gohring. It is highly radioactive, scarce and toxic element and has no uses outside …

Jun 28, 2025 · Protactinium (Pa) is a rare, radioactive metal with atomic number 91 and a silvery-gray appearance. It belongs to the actinide series and occurs naturally in trace amounts in uranium ores …

Protactinium (Pa), radioactive chemical element of the actinoid series of the periodic table, rarer than radium; its atomic number is 91. It occurs in all uranium ores to the extent of 0.34 part per million of …

Small amounts of protactinium are found naturally in uranium ores. It is also found in spent fuel rods from nuclear reactors, from which it is extracted. Mendeleev said there should be an element …

Protactinium was first isolated by Aristid V. Grosse in 1934. Protactinium is a rare, poisonous and expensive element that is present in uranium ores in very small amounts.

Protactinium is a highly radioactive metal belonging to the family of actinides and denoted by the chemical symbol Pa [1]. It has 27 isotopes with mass numbers ranging from 212 to 238 out of which …

Explore the intriguing world of Protactinium, Element 91. Learn about its history, properties, uses, and why it’s a fascinating subject in scientific research. From its discovery to its chemical reactions and …

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.

Protactinium is one of the rarest and most expensive naturally occurring elements. The element is an α-emitter and is a radiological hazard similar to polonium. Protactinium is a highly toxic and radioactive …