The energy of an electron in a hydrogen atom when present in $n=1$,$n=2$,and $n=3$ will be in the ratio of:

What is the angular momentum of an electron in the fourth orbit of a hydrogen atom?

The wavelength of the spectral line obtained in the spectrum of $Li^{2+}$ ion,when the transition takes place between two levels whose sum is $4$ and difference is $2$,is

In a hydrogen atom,the energy of an $e^-$ in an orbital is given by $E = \frac{-constant}{n^2} \ (kJ \ mol^{-1})$. Which of the following properties is constant according to the given equation?

In Bohr's atomic model,the radius $(r)$ and energy $(E)$ of an orbit $(n)$ are related as:

When an electron in a hydrogen atom jumps from an infinite state to the first stationary state,the wavelength of the emitted radiation will be ...... (Rydberg constant = $1.097 \times 10^7 \ m^{-1}$):