Protactinium Ionization Energy

The Protactinium Ionization Energy is the energy required to remove from atom one mole of electrons with subsequent production of positively charged ion of Protactinium.
Pa -> Pa⁺ + e^-
This process can be repeated many times, but the energy cost is increased dramatically. The general equation for the Protactinium is:
Pa^N+ -> Pa^(N+1)+ + e^-

Pa -> Pa¹⁺ = 568 kJ/mol = 135.89 Kcal/mol