The ratio of energies of photons produced due to the transition of an electron in a hydrogen atom from its $(i)$ second to first energy level and (ii) highest energy level to second energy level is: (in $3:1$)

In a sample of hydrogen-like atoms,all of which are in the ground state,a photon beam containing photons of various energies is passed. In the absorption spectrum,five dark lines are observed. The number of bright lines in the emission spectrum will be (assume that all transitions take place).

Assertion : Between any two given energy levels,the number of absorption transitions is always less than the number of emission transitions.
Reason : Absorption transitions start from the lowest energy level only and may end at any higher energy level. But emission transitions may start from any higher energy level and end at any energy level below it.

Which of the following transitions will have the highest emission wavelength?

The energy of an electron in the $n^{th}$ orbit of a hydrogen atom is given by $E_n = - \frac{13.6}{n^2} \ eV$. How much energy in $eV$ is required to move an electron from the first orbit to the third orbit?

The total energy of an electron in the ground state of a hydrogen atom is $-13.6 \text{ eV}$. The kinetic energy of an electron in the first excited state is.....$\text{ eV}$