Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can describe the photoelectric effect and define the work function as the minimum energy needed to remove an electron. (Guide: “What the photoelectric effect is”)
- I can explain why no electrons are emitted below the threshold frequency, however many photons arrive. (Guide: “The photon explanation”; Practice Q4, Q7d)
- I can explain why brighter light of the same frequency gives more electrons per second but the same K_max. (Guide: “The photon explanation”; Practice Q1)
- I can explain why the photoelectric effect is evidence that light is made of photons. (Guide: “What the experiments show” and “The photon explanation”; Practice Q1)
Calculation and skills
- I can use K_max = hf − φ with energies in consistent units, switching between joules and electron volts. (Guide: Worked example 1; Practice Q2, Q5)
- I can find the threshold frequency and threshold wavelength from the work function. (Guide: Worked example 1; Practice Q4, Q7c)
- I can use eV_s = K_max to link the stopping potential to the maximum kinetic energy. (Guide: “Measuring K_max: the stopping potential”; Practice Q2)
- I can calculate the number of photons per second from the power and wavelength of a source. (Practice Q5)
- I can plot V_s or K_max against frequency with suitable scales and read h and φ from the slope and intercept. (Guide: Worked example 2; Practice Q7)
Reasoning
- I can describe an experiment, with its circuit and measurements, that finds a work function. (Guide: Figure 1; Practice Q6)
- I can predict the factor by which the photon rate and K_max change when the power or frequency of the light changes. (Guide: Worked example 2; Practice Q5d)
- I can compare two metals from their K_max–frequency graphs and explain why the lines are parallel. (Guide: Figure 2; Practice Q3)
All ticked? Move on to Topic 15.6, Compton Scattering, or return to the course roadmap.