What are facts about protactinium?

Answer 1

it's radioactive, and is one of the rarest and most expensive naturally occurring elements. It costs 280$ per gram. It is of the actinide series; which means "radioactive rare earth", so it's related to other really cool elements like plutonium.

Answer 2

Protactinium is a radioactive element with the symbol Pa and atomic number 91. It is a silvery metallic element that can be found in trace amounts in uranium ores, but is primarily produced in laboratories. Protactinium has no significant commercial applications and is mainly used in scientific research and nuclear reactions studies.