DP I2I: Einstein/ Quantum Theory/ Black Body Radiation: (1 Viewer)

[Fosweb]

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Identify data sources, gather, process and analyse information and use available evidence to assess Einstein's contribution to quantum theory and its relation to black body radiation.

 

[Rev]

identify Einstein's contribution to quantum theory and its relation to black body radiation

Einstein applied Plancks quanta hypothesis to the photoelectric effect and used it to explain why in certain cases electrons were emitted and in other cases they were not. He explained the energy of the photon as (E=hf), and the (fi) as the energy required to release a photoelectron. Thus the energy of the released photoelectron was Ek=hf - (fi). For this to occur Einstein assumed that the photon must transfer either all or none of its energy. The intensity of light is proportional to the number of photons and atoms cannot be gangbanged to release photoelectrons.
The relationship to BBR is that the energy of light is quantised.

got it from a summary, hope it makes sense

 

[Dash]

LOL gangbanged!!

Wonder what will happen if we put that in the HSC exam paper

 

[Dangar]

Albert Einstein adopted a particle model and used Plancks theoretical explanation of black body radiation to apply it to the photoelectric effect.
Einstein propsed that:
-The energy of light is not evenly spread out over the wavefront, but is concentrated in packets of energy- photons.
-The energy of each photon is given by E = hf and this energy is used partly to break the electron away from its atom.
-A photon could give up all or none of its energy to one electron but it could not give only a part of it. Any excess energy gives the photoelectron its kinetic energy KE = hf work function
-Intense light was not light with more energy, it was more photons each with the same energy. Therefore as intensity of light of an appropriate frequency increased, photoemission increased as more photoelectrons could be emitted.
-Photons of light below the threshold frequency did not carry sufficient energy so no photoelectrons could be emitted regardless of the intensity.

Einstein applied it to something practical, and in doing so he made it credible. However recently there as been debate as to who actually was responsible for the quantum theory. Planck definitely put forward that the energy of a quantum is proportional to its frequency, but Planck did not propose a particle theory of light before Einstein. So is Einstein really the founder of quantum theory? Debate still rages among physics historians about the true originator of quantum theory.