$A$ hydrogen atom at the ground level absorbs a photon and is excited to $n=4$ level. The potential energy of the electron in the excited state is

When an electron in the ground state of a hydrogen atom is given $12.4 \, eV$ of energy,to which orbit will it transition?

Energy levels $A, B, C$ of a certain atom correspond to increasing values of energy,that is,$E_A < E_B < E_C$. If $\lambda_1, \lambda_2, \lambda_3$ are the wavelengths of radiations corresponding to the transitions $C$ to $B$,$B$ to $A$,and $C$ to $A$ respectively,as shown in the figure. Which of the following statements is correct?

For a certain hypothetical one-electron atom,the wavelength (in $\mathring{A}$) for the spectral lines for transition from $n = p$ to $n = 1$ is given by $\lambda = \frac{1500p^2}{p^2 - 1}$ (where $p > 1$). The ionization potential of this element must be ......$V$ (Take $hc = 12420 \text{ eV-} \mathring{A}$).

The binding energy of an electron in the ground state of a hydrogen atom is $13.6 \ eV$. What is the energy in $eV$ required to remove an electron from the first excited state of a $Li^{++}$ ion?

An electron in a stationary hydrogen atom jumps from the $4^{\text{th}}$ energy level to the ground level. The velocity that the photon acquired as a result of the electron transition will be ($h=$ Planck's constant,$R=$ Rydberg's constant,$m=$ mass of the photon).