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 Form 4 Physics Photoelectric effect online video lessons

The Quantum theory of light

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Answer Text:
Quantum theory of light
-Planck’s published his quantum hypothesis in 1901 which assumes that the transfer of energy between light radiation and matter
occurs in discrete units or packets.
- Einstein proposed that light is made up of packets of energy called photons which have no mass but they have momentum and energy given by;
E = h f
-The number of photons per unit area of the cross-section of a beam of light is proportional to its intensity. However the energy of a photon is proportional to its frequency and not the intensity of the light.