The ground state energy of a hydrogen atom is $-13.6 \text{ eV}$. When its electron is in the first excited state,its excitation energy is:

The energy of an electron in the $n^{th}$ orbit of a hydrogen atom is given by $E_n = -\frac{13.6}{n^2} \, eV$. How much energy in $eV$ is required to move an electron from the $n = 2$ orbit to the $n = 3$ orbit?

The ratio of the energies of the hydrogen atom in its first to second excited state is

Which of the following transitions will have the highest emission wavelength?

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

In an inelastic collision,an electron excites a hydrogen atom from its ground state to an $M$-shell state. $A$ second electron collides instantaneously with the excited hydrogen atom in the $M$-state and ionizes it. At least how much energy must the second electron transfer to the atom in the $M$-state?