Scattering:

As we have seen earlier, interaction of radiation along with matter, cause a momentary retention of radiant energy through atoms, ions or molecules because of their polarisation. If the polarised particles are small, destructive interference of the re-emitted radiations eliminates the remitted radiations within all the directions other than original path of the light. Now what we observe is the radiation transmitted within unaltered direction.  Keen experimental observations, therefore, revealed in which a minute fraction of the radiation is transmitted in all directions. This phenomenon is known as scattering and the radiation is referred to as scattered radiation. The intensity of the scattered radiation depends on the size of the particles constituting the medium.