Yttrium Ionization Energy

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

Y -> Y¹⁺ = 616 kJ/mol = 147.37 Kcal/mol
Y¹⁺ -> Y²⁺ = 1181 kJ/mol = 282.54 Kcal/mol
Y²⁺ -> Y³⁺ = 1980 kJ/mol = 473.68 Kcal/mol
Y³⁺ -> Y⁴⁺ = 5963 kJ/mol = 1426.56 Kcal/mol
Y⁴⁺ -> Y⁵⁺ = 7430 kJ/mol = 1777.51 Kcal/mol
Y⁵⁺ -> Y⁶⁺ = 8970 kJ/mol = 2145.93 Kcal/mol
Y⁶⁺ -> Y⁷⁺ = 11200 kJ/mol = 2679.43 Kcal/mol
Y⁷⁺ -> Y⁸⁺ = 12400 kJ/mol = 2966.51 Kcal/mol
Y⁸⁺ -> Y⁹⁺ = 14137 kJ/mol = 3382.06 Kcal/mol
Y⁹⁺ -> Y¹⁰⁺ = 18400 kJ/mol = 4401.91 Kcal/mol