1. Because of its scarcity, high radioactivity and high toxicity, there are currently no uses for protactinium outside scientific research, and for this purpose, protactinium is mostly extracted from spent nuclear fuel.

2. The Actinides is the collective name given to elements 90-103 in the periodic table, comprising thorium, protactinium, uranium, neptunium, plutonium, americium, curium, berkelium, californium, einsteinium, fermium, mendelevium, nobelium and lawrencium

3. Actinides are elements with atomic numbers from 90 to 103 following element Actinium. They include naturally occurring elements of thorium, protactinium and uranium and eleven transuranic i.e., artificially produced by nuclear reactions