A) Ultraviolet light with a wavelength of 200nm is incident upon gold surface in a vacuum chamber. What is teh wavelength of the most energetic electrons that are ejected from the surface?
Useful InformationL
Li 2.3eV
Ca 2.87 eV
Al 4.28 eV
Au 5.1ev
B) A photomultiplier tube detects photons by amplifying the current generated by the photoelectric effect. Which metal, lithium, calcium, aluminum or gold would you choose if you were trying to make a photomultiplier tube sensitive to the largest portion of the visible spectrum?