In a hydrogen sample,if the atoms are excited to states with principal quantum number $n = 20$,then the number of different wavelengths which may be observed in the spectrum is:

The difference between the frequencies of the first and second Lyman lines of the hydrogen atom is (where $R$ is the Rydberg constant and $c$ is the speed of light in vacuum).

If ${\lambda _{{\text{max}}}}$ is $6563 \text{ Å}$, then the wavelength of the second line of the Balmer series will be:

In a hydrogen atom,the wavelength of the light emitted during a transition from the $n = 3$ orbit to the $n = 2$ orbit is ${\lambda _0}$. What will be the wavelength of the light emitted during a transition from the $n = 4$ orbit to the $n = 2$ orbit?

$A$ hydrogen atom is excited from the ground state to another state with a principal quantum number equal to $4$. The number of spectral lines in the emission spectra will be:

The frequencies for the series limit of the Balmer and Paschen series are $f_1$ and $f_3$,respectively. If the frequency of the first line of the Balmer series is $f_2$,then the relation between $f_1, f_2$,and $f_3$ is: