H2 Physics 9478 · Topic 17
Quantum physics: evidence, states and spectra
Keep evidence tied to the claim it supports, add probability amplitudes before probabilities, and derive quantised energies from boundary conditions rather than treating them as arbitrary rules.
Before you begin
Study each reviewed objective cluster, then use the recorded diagnostic and repair plan. H2 practice evidence remains separate from H1 and H3.
Be comfortable with: Waves and Superposition objective chainEnergy and Fields objective chain
How the ideas connect
- Photon evidence, energy and momentum
- Matter-wave evidence and de Broglie wavelength
- Wavefunctions, probability density and superposition
- Uncertainty and the one-dimensional infinite square well
- Atomic energy levels and line spectra
Learn in order
Lesson route
Objective clusters
- 01Photon evidence, energy and momentum 19(a)–(c)Learn and apply 3 reviewed syllabus outcomes in one coherent cluster.
- 02Matter-wave evidence and de Broglie wavelength 19(d)–(e)Learn and apply 2 reviewed syllabus outcomes in one coherent cluster.
- 03Wavefunctions, probability density and superposition 19(f)–(g)Learn and apply 2 reviewed syllabus outcomes in one coherent cluster.
- 04Uncertainty and the one-dimensional infinite square well 19(h)–(j)Learn and apply 3 reviewed syllabus outcomes in one coherent cluster.
- 05Atomic energy levels and line spectra 19(k)–(m)Learn and apply 3 reviewed syllabus outcomes in one coherent cluster.
Prove your understanding
Practice and repair
Key ideas and reference
Use this concise Quantum physics: evidence, states and spectra checklist to locate the right objective cluster. Full definitions, derivations and worked examples stay in the linked lessons.
- Keep evidence tied to the claim it supports, add probability amplitudes before probabilities, and derive quantised energies from boundary conditions rather than treating them as arbitrary rules.
- Photon evidence, energy and momentum 19(a)–(c)
- Matter-wave evidence and de Broglie wavelength 19(d)–(e)
- Wavefunctions, probability density and superposition 19(f)–(g)
- Uncertainty and the one-dimensional infinite square well 19(h)–(j)
- Atomic energy levels and line spectra 19(k)–(m)
Course coverage and review details
Topic 19 states no explicit exclusions. The syllabus uses ΔxΔp ≳ h as written, rather than silently substituting a different convention. Infinite-square-well results apply to a one-dimensional well with ψ zero at both infinite walls and n = 1, 2, …. Photon and matter-wave evidence supports complementary quantum descriptions, not switching between classical identities. AL-QUANTUM-06 X-ray, Schrödinger-equation, finite-barrier, tunnelling and scanning-tunnelling extensions remain outside this official chain.
Coverage is reviewed against 9478 topic 19(a)–(m), PDF page 28. Selected-response progress does not by itself prove constructed, diagrammatic or practical performance.
Reviewed 2026-08-01