The minimum excitation energy of an electron revolving in the first orbit of hydrogen is (in $eV$)

If energy of $15 \ eV$ is given to an electron in the $4^{th}$ orbit,find its final energy when it comes out of the $H$-atom. (in $eV$)

If the binding energy of the electron in a hydrogen atom is $13.6 \ eV$,the energy required to remove the electron from the first excited state of $Li^{++}$ is.....$eV$.

If an electron in the excited state falls to the ground state,a photon of energy $5 \ eV$ is emitted. The wavelength of the photon is nearly: (in $nm$)

The kinetic energy of an electron in the $n^{th}$ orbit of a hydrogen-like species with atomic number $Z$ is $13.6 \frac{Z^2}{n^2} \ eV$. The potential energy of this electron in the same orbit will be:

The energy levels of an atom are shown in the figure. Which one of these transitions will result in the emission of a photon of wavelength $124.1 \, nm$? Given $(h = 6.62 \times 10^{-34} \, Js)$.