Assume that there is no repulsive force between the electrons in an atom, but the force between positive and negative charges is given by Coulomb’s law as usual. Under such circumstances, calculate the ground state energy of a He-atom.
For a he-nucleus z=2 and for ground n=1
Thus ground state energy of a He atom
Thus the ground state will have two electrons each of energy R and the total ground state energy would be -(4 X 13.6)eV=54.4eV