The binding energy of an electron in a $H$-atom with $n = 4$ is ....... $eV$. (Magnitude only)

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:

The energy levels of a hydrogen atom are shown below. The transition corresponding to the emission of the shortest wavelength is

The ratio of the energies of the electron in the hydrogen atom in the first and second excited states is

$A$ hydrogen sample is prepared in a particular excited state $A$ of quantum number $n_A=3$. The ground state energy of the hydrogen atom is $-|E|$. Photons of energy $\frac{|E|}{12}$ are absorbed by the sample,which results in the excitation of some electrons to an excited state $B$ of quantum number $n_B$. The value of $n_B$ is:

The energy required to remove an electron from the first excited state of $Li^{++}$ is ......... $eV$.