Helium can be excited from its ground state to its first excited state with an electric discharge. When this excited state helium relaxes back down to the ground state it can emit a photon of wavelength 125 nm. What is the energy of a photon with that wavelength? 1.6 x 10-18 J

1.6 x 10+18 J

5.6 x 10-23 J

5.6 x 10+23 J