In 1980, the International Atomic Energy Agency (IAEA) observed that protactinium, a chemical element generated in thorium reactors, could be separated and allowed to decay to isotopically pure ...

Atomic Number: 91 Atomic Symbol: Pa Atomic Weight: 231.03588 Melting Point: 2,862 F (1,572 C) Boiling Point: 7,232 F (4,000 C) Word Origin: The word protactinium comes from the Greek protos, meaning ...