Q134 · Practice questionComplex unfamiliar7 marks
QUESTION 134 (7 marks)
Electrons accelerated through strike a crystal. Assume non-relativistic motion.
a)[2 marks]
Calculate the electron kinetic energy in joules.
b)[3 marks]
Calculate the electron momentum and de Broglie wavelength.
c)[2 marks]
Explain why a diffraction pattern provides evidence for matter waves.
WORKED SOLUTION
7 marksPractice marking scheme
ANSWER
Diffraction/interference requires phase-dependent wave behaviour. Observing it for electrons is consistent with de Broglie matter waves and cannot be explained by purely classical point-particle trajectories.
Worked solution
Part (a): .
Part (b): (mK). .
Part (c): Diffraction/interference requires phase-dependent wave behaviour. Observing it for electrons is consistent with de Broglie matter waves and cannot be explained by purely classical point-particle trajectories.
Part (a): completes the requested reasoning and obtains a correct result.
Part (b): completes the requested reasoning and obtains a correct result.
Part (c): completes the requested reasoning and obtains a correct result.
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