Question 7
Part 1: Candidates were required to answer any five questions from this part.
Give three observations in support of de Broglie’s assumption that moving particles behave like waves.
Observation
Few candidates attempted this question. Almost all the candidates merely stated the general wave properties. They neither pay attention to the size of the particle nor give reference to moving particles as stipulated in the question. They just wrote diffraction, refraction, reflection to lose marks.
The expected answers are:
de-Broglie’s assumptions
- electrons show diffraction patterns
- electrons show refraction
- electrons show reflection
- electrons show interference
- electrons possess wavelength/frequency
- determination of molecular velocities in gases.