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........$eV$.

An electron in a hydrogen atom first jumps from the third excited state to the second excited state and then from the second excited state to the first excited state. The ratio of the wavelengths $\lambda_1 : \lambda_2$ emitted in the two cases is

In a hydrogen atom,the electron makes a transition from the $(n+1)^{\text{th}}$ level to the $n^{\text{th}}$ level. If $n >> 1$,the frequency of the radiation emitted is proportional to:

An electron with kinetic energy $E$ collides with a hydrogen atom in the ground state. The collision will be elastic

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

The first excited state of a hydrogen atom is $10.2 \ eV$ above the ground state. What temperature is needed to excite a hydrogen atom to its first excited state?