Answer:
E₀ = 9.5 eV
Step-by-step explanation:
In the processes of absorption, excitation and shocks the energy must be conserved therefore the energy before the shock is
E₀ = E_excitation + E_residual
E₀ = 5.8 + 3.7
E₀ = 9.5 eV
this is the energy of the electron before the collision