Zirconium Ionization Energy

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

Zr -> Zr¹⁺ = 660 kJ/mol = 157.89 Kcal/mol
Zr¹⁺ -> Zr²⁺ = 1267 kJ/mol = 303.11 Kcal/mol
Zr²⁺ -> Zr³⁺ = 2218 kJ/mol = 530.62 Kcal/mol
Zr³⁺ -> Zr⁴⁺ = 3313 kJ/mol = 792.58 Kcal/mol
Zr⁴⁺ -> Zr⁵⁺ = 7860 kJ/mol = 1880.38 Kcal/mol
Zr⁵⁺ -> Zr⁶⁺ = 9500 kJ/mol = 2272.73 Kcal/mol
Zr⁶⁺ -> Zr⁷⁺ = 11200 kJ/mol = 2679.43 Kcal/mol
Zr⁷⁺ -> Zr⁸⁺ = 13800 kJ/mol = 3301.44 Kcal/mol
Zr⁸⁺ -> Zr⁹⁺ = 15700 kJ/mol = 3755.98 Kcal/mol
Zr⁹⁺ -> Zr¹⁰⁺ = 17500 kJ/mol = 4186.60 Kcal/mol