The ratio of the magnitude of the kinetic energy to the potential energy of an electron in the $5^{\text{th}}$ excited state of a hydrogen atom is:

The number of spectral lines emitted by atomic hydrogen that is in the $4^{\text{th}}$ energy level 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:

Energy of the electron in $n^{th}$ orbit of hydrogen atom is given by $E_n = - \frac{13.6}{n^2} \ eV$. The amount of energy needed to transfer an electron from the first orbit to the third orbit is........$eV$.

The energy levels with transitions for an atom are shown in the figure. The transitions corresponding to the emission of radiation of maximum and minimum wavelength are respectively:

The figure shows the energy levels of a certain atom. When the electron de-excites from $3E$ to $E$,an electromagnetic wave of wavelength $\lambda$ is emitted. What is the wavelength of the electromagnetic wave emitted when the electron de-excites from $\frac{5E}{3}$ to $E$?