Wave-particle dualityAQA A-Level Physics: Mind map

Exam questions on Wave-particle duality

1. A lecturer explains that the behaviour of electrons and of light cannot be described by waves alone or by particles alone.
   Explain how the photoelectric effect suggests that electromagnetic waves have a particulate nature.2 marks
2. In a vacuum tube, electrons are accelerated through a potential difference and pass through a thin sheet of graphite. They produce a pattern of concentric rings on a fluorescent screen.
   Explain why the rings move closer to the centre when the accelerating potential difference is increased.2 marks
3. In an electron diffraction experiment an electron is accelerated from rest through a potential difference of 250 V in a vacuum.
   Calculate the speed of the electron.3 marks