An electron is excited to the n=3 energy level. On the diagram, draw arrows to show the possible electron transitions that can lead to the emission of a photon.

Show that a photon of wavelength 656 nm can be emitted from a hydrogen atom.

energy of photon is \(E = \left( {\frac{{6.63 \times {{10}^{ - 34}} \times 3 \times {{10}^8}}}{{656 \times {{10}^{ - 9}}}} = } \right)3.03 \times {10^{ - 19}}\left( {\rm{J}} \right)\);