Week 3 discussion, question 10

[Husnia Safi - 1K]

How did the discovery of photoelectric effect the world's understanding of the physics of quantum scale objects?

[Chem_Mod]

The particle-like behavior of light and the fact that energy of a light is quantized (photons)

[Chem_Mod]

Hi Husnia,

The strange thing about the photoelectric effect was that scientists expected that increasing the intensity, the number of photons, directed at a metal surface would cause the emission of electrons and that by increasing this intensity the kinetic energy of the ejected electrons would be greater. No matter what the frequency, eventually But instead, it didn't matter the number of photons bombarding the metal, those photons had to be of a particular frequency for electrons to be emitted regardless of how long the light was shone on the metal.

This changed the understanding of light from being just a wave to being particle like (wave particle duality). These particles or packets of energy, could cause electron emission so long as it has sufficient energy. There is a 1 to 1 correspondence between a photon and an electron. One high intensity will only knock out one electron. Many electrons will not knock out any electrons if they don't have equal to or greater than the work function of the metal.