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 name observations that classical physics could not explain and say why quantum theory is needed at atomic scales. (Guide: “Why a new theory was needed”)
- I can describe a photon: no mass, no charge, energy proportional to frequency, straight-line travel unless it interacts with matter. (Guide: “Light as photons”)
- I can explain that brighter light of one colour means more photons per second, not more energetic photons. (Guide: “Light as photons”; Practice Q5)
- I can describe a dim two-slit experiment and say which result is particle-like and which is wave-like. (Guide: Figure 1; Practice Q4)
- I can state that bound systems such as electrons in atoms have only certain allowed energies. (Guide: “Bound systems and quantized energy”)
Calculation and skills
- I can calculate a photon’s energy from its frequency or wavelength, in joules and in electron-volts. (Guide: Worked example 1; Practice Q1, Q5)
- I can find the number of photons per second from a beam’s power. (Guide: Worked example 1; Practice Q5)
- I can find the speed and wavelength of light in a medium from n, and explain why the photon energy does not change. (Guide: “How photons travel”; Practice Q2)
- I can calculate a de Broglie wavelength from mass and speed, or from an accelerating potential difference. (Guide: Worked example 2; Practice Q6, Q7)
- I can derive λ = h/√(2mqΔV) for a particle accelerated from rest. (Guide: “Matter waves”; Practice Q6)
Reasoning
- I can predict how λ changes when the speed, mass or accelerating voltage changes, using functional dependence. (Practice Q3, Q6b, Q6c)
- I can decide whether wave behaviour will be observable by comparing λ with the size of a gap or system. (Guide: “When do matter waves matter?”; Practice Q7)
- I can explain why charge plays no part in whether a particle has a de Broglie wavelength. (Practice Q7c)
All ticked? Move on to the Bohr model of atomic structure, or return to the course roadmap.