5. The energy levels for the He-Ne laser are shown below. According to the diagram, in the neon atom, the energy levels ??3 and ??5 are metastable levels. (a) Which transitions are the laser lines? (b) The values for the wavelengths of the transitions are given in nm. Determine the energey of the E4 and E2 leveles, as shown in the diagram. Note that the energy of the E3 and E5 in the neon atom are the same as those in the helium atom. (diagram on the next page)