Fig shows that energy levels of a mercury atom. Electrons with kinetic energies of 7.0 eV are introduced into mercury vapor. (a) Convert the energy levels to the system that sets the ground state at 0 eV. (b) What is the kinetic energy of an electron after an elastic collision with a mercury atom? (c ) What are the possible kinetic energies of an electron after an inelastic collision with a mercury atom? (d) What are the energies of the photons coming from the mercury vapor?

Explanation

(a) 0 eV, 4.9 eV, 6.7 eV, 8.8 eV and so on, (b) 7 eV, (c ) 2.12 eV, 0.3 eV, (d) 6.7 eV, 4.9 eV, 1.8 eV