HSC Physics — Module 7
de Broglie Wavelength — Flashcards & Quiz
Louis de Broglie proposed that every particle with momentum has an associated wavelength λ = h/p, extending wave-particle duality from photons to matter. HSC Physics Module 7 tests your ability to calculate de Broglie wavelengths for electrons and atomic nuclei, explain why macroscopic objects have negligible wavelengths, and link the concept to experimental evidence like the Davisson-Germer electron diffraction experiment and quantised orbits in the Bohr model.
Sample Flashcards
Q1: What is the de Broglie wavelength?
Louis de Broglie proposed that all matter has wave-like properties. The de Broglie wavelength: λ = h/p = h/(mv), where h is Planck's constant, p is momentum. Larger objects have negligibly small wavelengths; the effect is only significant for subatomic particles.
Sample Quiz Questions
Q1: A fast-moving electron has a shorter wavelength than a slow-moving electron.
Answer: TRUE
λ = h/(mv). As v increases, momentum increases, and wavelength decreases.
Q2: A macroscopic object like a cricket ball has a measurable de Broglie wavelength.
Answer: FALSE
While technically having a de Broglie wavelength, for a 0.15 kg ball at 30 m/s, λ ≈ 1.5 × 10⁻³⁴ m — far too small to measure or detect.
Related Concepts
Last updated: March 2026 · 1 flashcards · 2 quiz questions