A free electron and a free proton have the same speed. This means that, compared to the matter wave associated with the proton, the matter wave associated with the electron has:
A) a shorter wavelength and a greater frequency
B) a longer wavelength and a greater frequency
C) the same wavelength and the same frequency
D) the same wavelength and a greater frequency
E) a longer wavelength and a smaller frequency

Question

Quizplus · Accepted Answer

The de Broglie wavelength is inversely proportional to the mass of the particle. Since the electron is much lighter than the proton, at the same speed, the electron has a longer wavelength. The frequency is inversely proportional to the wavelength, so the electron has a smaller frequency.

A Free Electron and a Free Proton Have the Same