Question

Question 16

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

(a) Electron (b) Alpha particle $\left(H{e}^{2+}\right)$ (c) Neutron (d) Proton

Answer 1

From de-Broglie equation,

Wavelength, $\lambda =\frac{h}{mv}$

For same speed of different particles, i.e., electron, proton, neutron and $\alpha -$ particle,

$\lambda \propto \frac{1}{m}$

As h is constant. Greater the mass of matter waves, lesser is wavelength and vice-versa. In these matter waves, alpha particle $\left(H{e}^{2+}\right)$ has higher mass, therefore, shortest wavelength.