It 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

Answer

B

Explanation

From de-Broglie equation,
wavelength, `lamda=h/(mv)`
For same speed of different particles, i.e., electron proton, neutron and `alpha`-particle,
`lamdaprop1/m`
As h is constant, 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.