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

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

1.	If travelling at same speeds, which of the following matter waves have the shortest wavelength?
Answer» Electron Alpha PARTICLE `(He^(2+))` Neutron Proton Solution :`lamda = (h)/(MV)`. For same value of v, larger the value of mass m, shorter is the wavelength, `lamda`. HENCE `alpha`-particles have the largest mass