In the third orbit of a hydrogen atom,the energy of an electron is $E$. In the fifth orbit of a helium ion $(Z=2)$,the energy of an electron will be:

An electron of a stationary hydrogen atom transits from the fourth energy level to the ground level. The velocity of the hydrogen atom acquired as a result of photon emission will be:
{ $R =$ Rydberg constant,$m =$ mass of hydrogen atom }

The following diagram indicates the energy levels of a certain atom. When the system moves from the $2E$ level to the $E$ level,a photon of wavelength $\lambda$ is emitted. The wavelength of the photon produced during its transition from the $\frac{4E}{3}$ level to the $E$ level is

$A$ hydrogen atom absorbs radiation of wavelength $975 \, \text{\AA}$ to transition from the ground state to an excited state. To which energy level will the atom transition?

In an atom,an electron requires $47.2 \, eV$ of energy to transition from the $n = 2$ orbit to the $n = 3$ orbit. The atomic number $Z$ of the atom is:

In hydrogen and hydrogen-like atoms,the ratio of the difference of energies $E_{4n}-E_{2n}$ and $E_{2n}-E_{n}$ varies with its atomic number $Z$ and $n$ as: