Electrons behave as particles as a fixed number of electrons must be removed from an atom to make an ion.Particles have a charge to mass ratio (specific charge). This property was demonstrated by J. J. Thomson and is a property of particles.In 1913, Millikan found the charge of an electron in his oil-drop experiment. Electrons have a fixed mass and a fixed charge so they are particles.
Electrons fired at a thin crystal or through narrow slits will undergo diffraction and produce diffraction patterns and interference patterns when passing through double slits in experiments similar to Young's double-slit experiment.Diffraction and interference are not the behaviour of classical particles, but are properties of waves.So electrons behave as waves when they pass through a gap comparable to their de Broglie wavelength.The idea that things behave as waves under certain circumstances but as particles in other circumstances is called the wave-particle duality.
Electrons fired at a thin crystal or through narrow slits will undergo diffraction and produce diffraction patterns and interference patterns when passing through double slits in experiments similar to Young's double-slit experiment.Diffraction and interference are not the behaviour of classical particles, but are properties of waves.So electrons behave as waves when they pass through a gap comparable to their de Broglie wavelength.The idea that things behave as waves under certain circumstances but as particles in other circumstances is called the wave-particle duality.