Abstract

                                Radiation may be considered as the movement of energy through space, in either corpuscular or electromagnetic form. Corpuscular radiation consists of streams of atomic or sub- atomic particles which can transfer their kinetic energy to any matter with which they collide. The particles may be negatively charged such as the electrons in beta rays, positively charged as the helium nuclei of alpha rays, or electrically noutral as the neutrons. Electro-magnetic radiation, on the other hand, may behave as a self- propagating stream of particles, called photons, which cause electric and magnetic disturbances affecting the internal structure of matter and thus dissipate their energy. Radio waves, visible light, x-and gammarays are fundamentally similar classes of electromagnetic radiation.

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