Q5 · 2024 · Paper 2Simple familiar3 marks
QUESTION 5 (3 marks)
Explain the significance of the threshold frequency when incident light with a range of frequencies shines on a metal.
WORKED SOLUTION
3 marksQCAA guide · typeset solution
ANSWER
See worked solution below.
Worked solution
Threshold frequency is the minimum frequency of a
photon required to eject a photoelectron from the
surface of a metal. In this case, photons with
frequencies equal to or greater than the threshold
frequency will eject photoelectrons from the
surface of the metal, while photons with a lower
frequency will scatter off the metal’s surface.
• describes threshold frequency as the
minimum frequency of an incident photon
required to eject a photoelectron [1 mark]
• explains that photons with frequencies
greater than the threshold frequency will
have enough energy to eject a
photoelectron [1 mark]
• explains that photons with frequencies
less than the threshold frequency will be
scattered [1 mark]
One QCAA sample method typeset for web; criterion wording is adapted from the official marking guide.
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