Photoelectric Effect

[Natalie_Martinez_1I]

Can someone explain the photoelectric effect and its significance?

[sylvie_1D]

The photoelectric effect occurs when photons hit a metal surface and the electrons in the metal collide with the electrons in the photon, causing some of the electrons to absorb some of the energy and some of it to be given off. The corresponding equation is : (E= hv) - ( the work function or threshold energy) =( kinetic energy or the excess)

[Madison Hacker 1L]

It also proves that light is not just made of waves, which was previously thought. It is instead made of particles.

[Andrew Evans - 1G]

Yeah, like Madison said, the photoelectric experiment provided an example of electromagnetic radiation (light) behaving unlike a wave. For a wave, you can increase the energy by increasing the intensity (increasing the amplitude). However, in the experiment, shining brighter light did not eject electrons from the metal. So the energy of light must not be dependent on the amplitude/intensity. Instead, they found out that increasing the frequency of light caused electrons to be ejected, so energy must be correlated with wavelength.

So in all, the photoelectric effect proposed a photon model for light in which energy is transferred on a single photon by single electron basis. Increasing the intensity of light would be the same as having a bunch of photon, but if one photon doesn't have the energy/frequency to eject the electron, nothing's gonna ding dang happen.

-Andrew Evans
Section 1G

[Vivian Gonzalez 1A]

The photoelectric effect measures the energy needed to remove electrons from different metals. In the photoelectric experiment, light sources with long wavelengths cannot eject e-, however, light sources with short wavelengths (high frequencies) can eject e-.