Q:  What is the energy of a photon produced by this transition?

         E  =   E(n=1)                -          E(n=0) 

            =   0.269 eV * (1 + 1/2)  -   0.269 eV * (0 + 1/2)

            =   0.269 eV



  Q:  What is the wavelength of the photon?

                       1240 eV*nm
          lambda  =  --------------  =  4610 nm  =  4.6 micrometers
                       0.269 eV


  Q:  In what region of the electromagnetic spectrum does this line appear?


           micrometers = near-IR