Which of the following pairs of phenomena helps in the resolution of the wave-particle paradox of matter?

Analyze the question

The wave-particle paradox (duality) of matter asks: do particles such as electrons behave like waves, and do waves such as light behave like particles? Resolving it needs a pair of phenomena, one showing wave behaviour and one showing particle behaviour.

Concept

• Wave nature is shown by interference, diffraction, polarization and refraction.
• Particle nature is shown by the photoelectric effect, the Compton effect, and emission and absorption of light in quanta.
• De Broglie proposed that matter has wavelength λ = h/mv. This was confirmed by electron diffraction (Davisson–Germer experiment).

Checking the options

• A. Compton effect (particle nature of light) and thermionic emission (electrons released by heat). Thermionic emission shows no wave behaviour, so this pair is not a good fit.
• B. Electron diffraction (wave nature of electrons, which are matter) and refraction (a wave property). Both show wave behaviour, but electron diffraction is the key evidence for matter waves, so this is the nearest fit among the options.
• C. Emission and absorption of light show only the quantum (particle) nature of light.
• D. Interference and polarization are both wave phenomena of light. Neither shows particle behaviour.
• E. Reflection and the photoelectric effect. Reflection is explained by both models, so it does not distinguish them. The photoelectric effect shows the particle nature of light.

Honest note

Strictly, the best pair would be one wave phenomenon plus one particle phenomenon. No option gives that perfectly for matter. Option B is the only one that includes electron diffraction, the experimental evidence that matter (electrons) behaves as a wave, and that is what resolves the paradox for matter.

Answer: B

Tip: When you see "wave-particle duality of matter", look for electron diffraction (Davisson–Germer) in the options. For duality of light, look for the photoelectric effect paired with interference or diffraction.