a) Photoelectric effect

• state what the frequency of a photon is proportional to

• state what the intensity of photons is related to

• energy of the photon

• number of photons emitted per unit time

• define threshold frequency

• define work function

• minimum frequency required to free an electron

• minimum energy required to free an electron

• define photoelectric effect

• when EM radiation of the threshold frequency is incident on a metal surface

• electrons gain kinetic energy

• instantly escape the metal surface

• state the observation of electron emission from the photoelectric effect

• electrons gain enough kinetic energy → escape instantly

• higher frequency → more kinetic energy gained

• higher intensity → more electrons emitted

• state the implication of the nature of EM radiation from the photoelectric effect

• increase in intensity → increase in energy transferred to the metal → no increase in kinetic energy gained by electrons

• kinetic energy gained by electrons → not dependent on intensity

• EM radiation is not a wave

• explain the observations from the photoelectric effect

• electrons on metal surface → require a certain amount of kinetic energy to escape

• one photon → transfers its energy to one electron

• energy of a photon → dependent on frequency → not dependent on intensity

• at threshold frequency → each photon has enough energy to free one electron

• at higher intensity → more photons have enough energy to free more electrons

• state what the frequency of EM radiation is proportional to in the photoelectric effect

• state what the intensity of EM radiation is proportional to in the photoelectric effect

• kinetic energy gained by electrons

• rate of electron emission