How much energy is required to ionize a hydrogen atom in its ground (or lowest energy) state? In J?

Answer 1

This is the opposite of the binding energy of the lowest state given by:

E = me^4/[8E^2h^2] please forgive the crude way I had to write this formula - limitations of the keyboard.

= (9.11x10^-31 kg)(1.6x10^-19 C)^4
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(8)(8.85x 10^-12 C^2/Nm^2)^2(6.63 x 10^-34 Js)^2

= 2.17 x 10^-18 J or 13.6 electron volts