Rubidium Ionization Energy

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

Rb -> Rb¹⁺ = 403 kJ/mol = 96.41 Kcal/mol
Rb¹⁺ -> Rb²⁺ = 2632 kJ/mol = 629.67 Kcal/mol
Rb²⁺ -> Rb³⁺ = 3900 kJ/mol = 933.01 Kcal/mol
Rb³⁺ -> Rb⁴⁺ = 5080 kJ/mol = 1215.31 Kcal/mol
Rb⁴⁺ -> Rb⁵⁺ = 6850 kJ/mol = 1638.76 Kcal/mol
Rb⁵⁺ -> Rb⁶⁺ = 8140 kJ/mol = 1947.37 Kcal/mol
Rb⁶⁺ -> Rb⁷⁺ = 9570 kJ/mol = 2289.47 Kcal/mol
Rb⁷⁺ -> Rb⁸⁺ = 13100 kJ/mol = 3133.97 Kcal/mol
Rb⁸⁺ -> Rb⁹⁺ = 14800 kJ/mol = 3540.67 Kcal/mol
Rb⁹⁺ -> Rb¹⁰⁺ = 26740 kJ/mol = 6397.13 Kcal/mol