A proton and an electron each have the same de Broglie wavelength.(i)Which has the lower speed,and (ii)which has the lower kinetic energy?
A) (i)the electron,(ii)the electron
B) (i)the electron,(ii)Either one can have the greater kinetic energy.
C) (i)the proton,(ii)Either one can have the greater kinetic energy.
D) (i)the proton,(ii)the proton

Question

Quizplus · Accepted Answer

The de Broglie wavelength is inversely proportional to momentum. Since the proton is much more massive than the electron, for the same wavelength, the proton must have a lower speed. Kinetic energy depends on both mass and speed, and since the proton has a much larger mass, it will have a lower kinetic energy for the same wavelength.

A Proton and an Electron Each Have the Same De