12.2 The Wave Nature Of Matter

Question 1

What does the De Broglie wavelength state?

Answer 1

All moving particles electrically charged or neutral show wave behaviour, with a characteristic wavelength given by
lambda = h/p where h is the Planck’s constant and p is the momentum of the particle.

Question 2

How can the De Broglie wavelength be verified by an experiment?

Answer 2

A beam of electrons is accelerated through a known potential difference and directed at a crystal from which it scatters. The detector which can be rotated shows peaks in the number of scattered electrons at specific angles. The results are consistent with the diffraction of waves for a wavelength equal to the de Broglie wavelength of the electrons.