Explanation : The phenomena such as interference, diffraction, and polarization can only be explained when light is treated as a wave whereas photoelectric effect, line spectra, and the production and scattering of x-rays demonstrate the particle nature of light. The photoelectric effect supports a particle theory of light in that it behaves like an elastic collision (one that conserves mechanical energy) between two particles, the photon of light and the electron of the metal. ....Read more