Question

The total energy of a hydrogen atom in its ground state is -13.6 eV. If the potential energy in the first excited state is taken as zero then the total energy in the ground state will be

(a) -3.4 eV

(b) 3.4 eV

(c) -6.8 eV

(d) 6.8 eV

Answer 1

Correct Answer is: (c) -6.8 eV

The total energy in the first excited state is - 13.6/4 eV = -3.4 eV.

This consists of the kinetic energy of 3.4 eV and the potential energy of -6.8 eV. In order to take the PE here as zero, we add 6.8 eV to all energy levels. The total energy in the ground state then becomes (- 13.6 + 6.8) eV = - 6.8 eV.