Wave/particle duality
Q1. Electrons exhibit wave properties.
(a) What phenomenon can be used to demonstrate the wave properties of electrons? Details of any apparatus used are not required.
electron diffraction OR electron interference/superposition 
(1 mark)
(b) Calculate the de Broglie wavelength of electrons travelling at a speed of 4.50 × 105 m s–1.
λ dB= h/p = h/mv
λ dB = 6.63 × 10–34/(9.11 × 10–31 × 4.50 × 105)
λ dB = 1.6 × 10–9 m
(2 marks)
(c) The muon has a mass equal to 207 times the mass of an electron. Calculate the speed of muons with the same de Broglie wavelength as the electrons in part (b).
v = h/mλ dB
v = 6.63 × 10–34/(1.6 × 10–7x (207 × 9.11 × 10–31 ))
v = 2170
v = 2200 m s–1
(3 marks)
(Total 6 marks)
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