In a hydrogen-like atom,an electron makes a transition from an energy level with principal quantum number $n$ to another with principal quantum number $(n - 1)$. If $n >> 1$,the frequency of the emitted radiation is proportional to:

$A$ hydrogen atom emits blue light when it changes from the $n = 4$ energy level to the $n = 2$ level. Which colour of light would the atom emit when it changes from the $n = 5$ level to the $n = 2$ level?

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.

In the $n^{th}$ orbit,the energy of an electron is given by $E_n = -\frac{13.6}{n^2} \text{ eV}$ for a hydrogen atom. The energy required to excite the electron from the first orbit $(n=1)$ to the second orbit $(n=2)$ will be..... eV.

During the transition of an electron from state $A$ to state $C$ of a Bohr atom,the wavelength of the emitted radiation is $2000 \ \mathring A$ and it becomes $6000 \ \mathring A$ when the electron jumps from state $B$ to state $C.$ Then the wavelength of the radiation emitted during the transition of electrons from state $A$ to state $B$ is

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