$A$ hydrogen atom is excited from the ground state to the energy level $n = 3$. According to Bohr's model,the number of spectral lines emitted is:

The light emitted in the transition $n = 3$ to $n = 2$ (where $n$ is the principal quantum number of the state) in hydrogen is called $H_{\alpha}$-light. Find the maximum work function that a metal can have so that $H_{\alpha}$-light can emit photoelectrons from it. (in $\text{ eV}$)

In which of the following series does the $121.5 \ nm$ line of the spectrum of the hydrogen atom lie?

$A$ hydrogen atom in its ground state absorbs a photon and the electron transitions to the $5^{th}$ orbit. When the excited atom returns to its ground state,it emits photons of various energies. What is the maximum number of spectral lines that can be obtained in this process?

The ratio of the largest to shortest wavelengths in the Lyman series of hydrogen spectra is

In the hydrogen spectrum,the shortest wavelength in the Balmer series is $\lambda$. The shortest wavelength in the Brackett series is $........\,\lambda$.