Inner shell electrons in atoms moving from one energy level to another lower energy level produce

The energy of a hydrogen atom in the $n^{th}$ orbit is $E_n$. What will be the energy in the $n^{th}$ orbit of a singly ionized helium atom?

If the potential energy of a hydrogen atom in the first excited state is assumed to be zero, then the total energy of the $n = \infty$ state is,

The energy levels of an electron in an atom are shown. Which transition of the electron represents the emission of a photon with the highest energy?

In a hydrogen atom,which of the following transitions will emit a photon of the highest frequency?

An electron in a hydrogen atom undergoes a transition from an orbit with quantum number $n_i$ to another with quantum number $n_f$. $V_i$ and $V_f$ are respectively the initial and final potential energies of the electron. If $\frac{V_i}{V_f} = 6.25$,then the smallest possible $n_f$ is: