Q. Visible light is incident on a sodium surface in a photoelectric effect experiment.

(1) Given the wavelength of visible light is from 380 to 730nm and the work function of sodium is 2.28eV,

(i) compute the highest kinetic energy of the photoelectron emitted from the surface.

(ii) Sketch a graph of highest kinetic energy, KEmax against visible light frequency, v for this experiment. Label the threshold frequency, vo.

(2) If the sodium target is replaced with another material with a lower work function, what would happen to your graph in part (1)(ii)? Describe your answer.

2. (1) examine what is meant by the nuclear atomic model.

(2) With the help of a diagram and appropriate equations, show how Geiger and Marsden prove the nuclear atomic model.

3. (1) What is meant by the wave function of a particle?

(2) A beam of electrons passes by a single slit and a beam of protons passes by a second, but identical slit. If the electrons and protons have the similar speed, that beam would experience the greatest amount of diffraction? Clarify your answer.

(3) A proton is confined within an atomic nucleus of diam 4.0 fm. Can we know with certainty if the proton is really at rest? Describe your answer.