If an electron in the excited state falls to the ground state,a photon of energy $5 \ eV$ is emitted. The wavelength of the photon is nearly: (in $nm$)

In Bohr's atomic model of hydrogen,let $K$,$P$ and $E$ be the kinetic energy,potential energy and total energy of the electron,respectively. Choose the correct option when the electron undergoes transitions to a higher level.

Total energy of an electron in an excited state of a hydrogen atom is $-3.4 \text{ eV}$. Find the kinetic and potential energy of the electron in this state.

$A$ hydrogen atom initially in the ground level absorbs a photon,which excites it to the $n = 4$ level. Determine the wavelength and frequency of the photon.

As the quantum number $n$ increases,the difference in energy between consecutive energy levels

When an electron in a hydrogen atom jumps from the third orbit to the second orbit,it emits a photon of wavelength $\lambda$. When it jumps from the fourth orbit to the third orbit,the wavelength emitted by the photon will be