Wave-particle duality is the statement that all particles exhibit both wave and particle properties. Wave-particle duality is an ongoing problem in modern physics. Most physicists accept wave-particle duality as the best explanation for a broad range of observed phenomena’s without specific laws attributed to them, however it is very controversial.
Although wave-particle duality is intertwined with the rest of quantum mechanics it is possible to separate specific applications of wave-particle duality. It is used in electron microscopy, where the small wavelengths associated with the electrons can be used to view objects much smaller than what is visible using visible light. And neutron diffraction used neutrons with a wavelength of about 0.1nm, the typical spacing of atoms in a solid, to determine the structure of solids.