The de Broglie wavelength is given by : λ=h/p where p is the momentum of the particle. For which of the following the de Broglie wavelength will be the least?

electron proton neutron alpha particle ( 2 electrons, 2 protons, 2 neutrons)

alpha particle ( 2 electrons, 2 protons, 2 neutrons)

alpha particle. λ=h/p=h/mv  ⇒ λ∝1/m ∴ larger the mass, lesser the de Broglie wavelength.