Lisa, read this! Try to make sense out of it. Light Behaves Like A Stream of ParticlesIn 1905, Albert Einstein described the photoelectric effect- the emission of electrons from metal surfaces on which light shines.Each photon must have an energy equal to Plancks constant times the frequency of the light:Ephoton = hνIf a photon strikes the surface of the metal with a specific amount of energy - called the work function - an electron in the metal can absorb that energy and use it to overcome the attractive forces that hold it in the metal.If the photon has less energy than the work function, electrons do not escape from the metal. If the photon has more energy than the work function, the excess energy appears as the kinetic energy of the emitted electrons.According to Einsteins theory, light must possess both wave-like and particle-like characteristics and, depending on the situation, will behave more like a wave or more like particles. This is known as the dual nature of light - and is the concept which won the Nobel Prize for Einstein - not E=mc2 or the theory of relativity.
Posted on: Tue, 30 Sep 2014 17:08:56 +0000
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