From Conservapedia
Jump to: navigation, search
Name Protactinium
Symbol Pa
Atomic number 91
Atomic mass 231.03588 amu
Normal state Solid
Classification Metallic
Crystal structure Orthorhombic
Color silvery metallic, radioactive
Date of discovery 1913
Name of discoverer Kasimir Fajans and O.H. Göhring
Name origin From the Greek Protos meaning first.
Uses None
Obtained from Occurs in minute trace amounts in uranium ores, but chiefly amongst the fission products of uranium, thorium, and plutonium. In 1961 the UK Atomic Energy Authority produced 125g of pure protactinium from uranium fuel elements, which represents the major world stock of protactinium.