Quantum Exam Style Questions

a) The work function of a metal is the amount of energy required to have photoelectrons emitted from the surface of the metal.
b) When an electron is hit by a photon that is under the threshold frequency, the electron does not gain enough energy to be emitted as a photoelectron. This means the electron is emmitted again and no change occurs.
c) The threshold frequency shows that light acts as a particle. If light acted as a wave, then energy would build up over time and all of the photoelectrons would be emitted from the metal. However, this doesnt happen, therefore proving light is made of photons.
d) \(6.8\times 10^{-19}\)
e) \(3.0\times10^{-18}-6.8\times 10^{-19}=2.32\times 10^{-18}\)
f) Stopping potential = \(\frac{E_{k(max)}}{\text{electron charge}}\)
\(\frac{2.32\times 10^{-18}}{1.6\times10^{-19}}=14.5=14\)