An electron collides elastically with an $H$-like atom and excites it from the ground state to $n = 3$. Find the energy transferred to the $H$-like atom in $eV$.

The recoil speed of a hydrogen atom after it emits a photon in going from $n = 5$ state to $n = 1$ state will be ..... $m/s$.

In the hydrogen atom,if the reference level of potential energy is assumed to be zero at the ground state level,choose the incorrect statement.

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).

The ratio of the kinetic energies of the electrons in the third and fourth excited states of the hydrogen atom is

The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with maximum wavelength?