The ionisation potential of a hydrogen atom is $13.6 \, V$. The energy required to remove an electron in the $n = 2$ state of the hydrogen atom is.....$eV$.

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 $eV$.

Which of the transitions in a hydrogen atom emits a photon of the lowest frequency? ($n =$ quantum number)

The ratio of energies of photons produced due to the transition of an electron in a hydrogen atom from its $(i)$ second to first energy level and (ii) highest energy level to second energy level is: (in $3:1$)

The potential energy of the orbital electron in the ground state of a hydrogen atom is $-E$. What is its kinetic energy?

The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true?