The ionization energy of a hydrogen atom is 13.6 eV. When a hydrogen atom absorbs a photon with this energy, the electron is ejected from the atom. 

(a) What are the frequency and wavelength of a photon with this energy? Where does this photon lie in the electromagnetic spectrum? Could you see light with this frequency? 

(b) When a photon has an energy greater than 13.6 eV, the “extra” energy (the energy in excess of 13.6 eV) goes into kinetic energy of the ejected electron. If a hydrogen atom absorbs a photon with an energy of 15.0 eV, what are the kinetic energy and speed of the ejected electron? 

(c) When the light intensity is very high, it is possible for a hydrogen atom to absorb two photons simultaneously. If a hydrogen atom absorbs two photons of equal energy and the atom is just barely ionized, what are the frequency and wavelength of these photons? Could you see this light?