The ground state energy of a hydrogen atom is $-13.6 \, eV$. When its electron is in the first excited state,its excitation energy is ...... $eV$.

The diagram below shows the lowest four energy levels for an electron in a hypothetical atom. The electron is excited to the $-1\,eV$ level and transitions to the lowest energy state $(-12\,eV)$ by emitting exactly two photons. Which of the following energies could not belong to either of the photons (in $eV$)?

The ground state energy of the hydrogen atom is $-13.6 \ eV$. The kinetic and potential energy of the electron in the second excited state are,respectively:

The energy of a hydrogen atom in its ground state is $-13.6 \ eV$. The energy of the level corresponding to the quantum number $n = 2$ (first excited state) in the hydrogen atom is......$eV$.

The diagram shows the lowest four energy levels for an electron in a hypothetical atom. The electron is excited to the $-1\, eV$ level and transitions to the lowest energy state by emitting exactly two photons. Which of the following energies could not belong to either of the photons (in $, eV$)?

Some energy levels of a molecule are shown in the figure. The ratio of the wavelengths $r = \frac{\lambda_1}{\lambda_2}$ is given by