Past exam of the chemistry A course of the University of Cambridge / 2021 / Paper 1 / A1 / b / iv / Solution

For a $2p$ atomic orbital, $l=1$. The radial factor obeysSubstitution into the radial Schrödinger equation for a central potential givesThus the energy eigenvalue isThe normalization constant cancels; $E_{\mathrm{h}}$ is the Hartree energy.