When light of wavelength 300 nm is incident upon potassium, the emitted electrons, due to the photoelectric effect, have a maximum kinetic energy of 2.03 eV. (a) What is the energy of the incident photon? (b) What is the work function for potassium? (c) What would be the stopping potential if the incident light had a wavelength of 430 nm? (d) What is the threshold wavelength for the photoelectric effect with potassium?