The energy of a photon is calculated by ......

Which one of the following corresponds to the wavelength of a line in the Balmer series of the $H$ atom spectrum? $(R =$ Rydberg constant$)$

The wavelength of a spectral line emitted by a hydrogen atom in the Lyman series is $\frac{16}{15 R} \ cm$. What is the value of $n_2$? $(R = \text{Rydberg constant})$

The binding energy of an $e^-$ in the ground state of a hydrogen atom is $13.6 \ eV$. The energy required to remove an electron from the ground state of a $He^+$ ion is:

The total energy of the electron in the hydrogen atom in the ground state is $-13.6 \, eV$. What is the stopping potential in volts required to remove this electron from the ground state?

Calculate the energy released when an electron in a hydrogen atom transitions from the $3^{rd}$ energy level to the $2^{nd}$ energy level.