CHAPTER 9

9.1 (a) State Planck’s quantum theory

9.1 (b) Distinguish between Planck’s quantum theory and classical theory of energy

9.1 (c) Use Einstein’s equation for photon energy

9.2 (a) Define photoelectric effect

9.2 (b) Explain the phenomenon of photoelectric effect by sketching the diagram of photoelectric effect experimental set-up

9.2 (c) Define threshold frequency, work function and stopping potential

9.2 (d) Explain the failure of classical theory to justify photoelectric effect

9.2 (e) Analyse by using graphs and equations the observations of photoelectric effect experiment in terms of the dependence of:

i. Kinetic energy of photoelectron on the frequency of light

ii. Photoelectric current on intensity of incident light

iii. Work function and threshold frequency on the types of metal surface

9.2 (f) Use Einstein’s photoelectric equation, Kₘₐₓ = eV = hf − Wₒ