(a)[2]
State what is meant by the de Broglie wavelength.
(b(i))[5]
An electron starts from rest in a vacuum and is accelerated through a potential difference of $4.7\,\text{kV}$. Calculate the de Broglie wavelength of the accelerated electron.
(b(ii))[2]
Using your answer to part (i), suggest why these electrons may help in understanding crystal structure.