Question

When moving with the same velocity which one of the following particles has the largest de Broglie wavelength and why? (a) Electron (b) Proton (c) α-particle.

Answer 1

When moving with the “same velocity” electron has the largest de Broglie wavelength. It is because, de-Broglie equation states that wavelength of the particle is “inversely proportional” to its mass. The mass of electron, proton, and neutron are 0.00054, 1.00727, and 1.00867 respectively.

When the mass of all the three particles is compared, the particle with less mass is electron. Thus, less mass means more wavelengths. Hence, it can be inferred that electron has the “largest” “de Broglie wavelength”.