Photoelectric Effect: Green vs Indigo Light

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Discussion Overview

The discussion revolves around the photoelectric effect, specifically examining the behavior of electrons ejected from a surface when illuminated by different colors of light, namely green and indigo. Participants explore whether the intensity and frequency of the light affect the number of photoelectrons ejected, considering the work function of the material involved.

Discussion Character

  • Homework-related
  • Exploratory
  • Technical explanation

Main Points Raised

  • One participant asserts that if green light can eject electrons, then indigo light, being of higher frequency, should also be able to eject electrons, but questions whether it can increase the number of ejected electrons.
  • Another participant emphasizes the importance of considering the energy of a single photon in relation to the work function, questioning what occurs when the energy is less than, equal to, or greater than the work function.
  • A different participant suggests that an intense beam of indigo light might release more electrons than green light, depending on the number of available electrons in deeper shells of the metal plate.
  • One participant highlights the need to think in terms of single photons, reinforcing the concept that the photoelectric effect is fundamentally about individual photon interactions with electrons.
  • Another participant points out the ambiguity in the original question regarding the intensity of light and suggests that it should be clarified whether the number of photons is assumed to be the same in each case.

Areas of Agreement / Disagreement

Participants express differing views on the impact of light intensity and frequency on the number of ejected electrons, indicating that multiple competing perspectives exist without a clear consensus on the effects of indigo light compared to green light.

Contextual Notes

The discussion does not resolve the ambiguity regarding the intensity of light and its implications for the number of photons involved in the photoelectric effect. Assumptions about the conditions under which the experiment is conducted remain unspecified.

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Homework Statement



A surface ejects electrons when hit by green light but not when hit by yellow light. Will the number of photoelectrons ejected be changed if the surface is hit by indigo light?

A) yes B) No C) yes, if the indigo light is quite intense

Homework Equations



E = hv (h is plank's constant and v is frequency of photon)

The Attempt at a Solution



I know only one photon is necessary for ejection of a photo electron if it has energy more than the work function, so if the electrons are removed by green light, they must be removed by indigo light as well, but can the number of electrons released increase, supposing that indigo light can further eject electrons of deeper shells?
 
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Think about the collision of a single photon of light, with a single electron on the surface. What happens when the energy is smaller than the work function? The same as the work function? Greater than the work function?---In this case, what happens to the excess energy?
 
I know that if the energy of the photon is equal to or more than the work function, the electron will be released and the excess energy, if any, will be converted into the kinetic energy of the electron.

But imagine this situation, a metal plate, supposedly containing more than two shells of electrons, and a beam of green light incident on it is able to release the electrons.
If instead of the green light an intense indigo light is shone on the plate, can it relese more electrons than the green light?
 
I was going somewhere with my questions... You are right about the single photon case. Remember that the biggest lesson learned from the photoelectric effect is that it requires thinking about it in terms of single quanta of light (photons), even if they're from a laser beam.
 
Question doesn't say anything about intensity of the light, which makes it ambiguous. I guess we are to assume in each case number of photons is identical, but it should be spelled out.
 

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