If travelling at same speeds, which of the following matter waves have the shortest wave­length ?

Options

A. Electron
B. Alpha particle `(He^(2+))`
C. Neutron
D. Proton

Explanation

According to de-Broglie equation, wavelength, `lambda=(h)/(mv)` For same speed of different particles, i.e., electron, proton, neutron and `alpha` particle `lambda` particle `lambda prop (1)/(m)`
h is constant. So, Greater the mass of matter waves, lesser is wavelength and vice-versa. In these matter waves, alpha particle `(He^(2+))` has higher mass, therefore, shortest wavelength.