Question

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

• A. Electron
• B. Alpha particle ($He^{2 +}$)
• C. Neutron
• D. Proton

Answer 1

Answer: (B)

Alpha particle ($He^{2 +}$)

Answer 2

: $\lambda = \frac{h}{mv}$if v is same, then higher the value of m means lower will be the value of $\lambda$.

Name	Electron	Proton	Neutron	α - particle (He2+)
Mass/u	0.00054	1.00727	1.00867	4.0026

Thus, $\alpha$ - particle has the largest mass i.e., shortest wavelength.