Wave particle duality
In the first quarter of the twentieth century physicists began to realize that particles did not always behave like particles – they could behave like waves. They called this wave-particle duality.
This theory suggests that there is no basic distinction between a particle and a wave. The differences that we observe arise simply from the particular experiment that we are doing at the time.
As with quantum theory, this is a section of the course that candidates will find completely new. They are unlikely to have already met the wave nature of particles or the wave nature of electrons bound within atoms.