Answer to Question #119702 in Atomic and Nuclear Physics for Dheeraj Kumar Godara

Question

The energy required to remove both electrons from the Helium from its ground state is 79eV. Ho much energy is required to ionize Helium(remove one electron)?

Answer 1

The energy required to remove one electron from the ground state of $He^+$ (Hydrogen like atom )atom is

$E_n=\frac{13.6 Z^2}{n^2}$ eV

For ground state $n=1$ ,

$E_1=\frac{13.6 (2)^2}{1^2}=54.4 eV$

Given that the energy required to remove both electrons from the Helium from its ground state is $79eV$ .

So the energy required to ionize Helium is

= $79 eV -54.4 eV=24.6 eV$