Class 12 NEET Physics Dual Nature of Matter and Radiation

de Broglie wavelength for a particle is given by λ=

h

p

=

h

mv

, where m,v and p are the mass, velocity and momentum respectively. h is Planck's constant. Now, since all the particles are moving with same velocity, the particle with least mass will have maximum de-Broglie wavelength. Out of the given four particles (proton, neutron, α -particles, i.e., He nucleus and β -particles, i.e., electrons) β -particle has the lowest mass and therefore it has maximum wavelength.