How is the emission spectrum formed? (4)

1) passing an electric discharge through a gas = electron gets promoted to a higher energy level ground state -> excited state 2) bec the electron is unstable in the higher level it will fall down to a lower energy level 3) this extra energy is given out as a photon of light = line in spectrum = evidence of electrons being in energy levels as the electrons can only have certain amount of energy CONC= photon of light given out from electron when it goes from high energy level = low after being excited from an electric discharge