Photoelectric Effect: Green vs Indigo Light

In summary, the question is asking if the number of photoelectrons ejected from a surface will change when hit by indigo light, given that it ejects electrons when hit by green light but not when hit by yellow light. The answer is that it depends on the intensity of the indigo light, as the energy of a single photon is enough to release an electron, but it is unclear from the question whether the intensity of the light is the same for both green and indigo light. It is important to consider the concept of single photon interactions in the photoelectric effect, regardless of the intensity of the light.
  • #1
AlchemistK
158
0

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?
 
Physics news on Phys.org
  • #2
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?
 
  • #3
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?
 
  • #4
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.
 
  • #5
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.
 

Related to Photoelectric Effect: Green vs Indigo Light

1. What is the photoelectric effect?

The photoelectric effect is the phenomenon where electrons are emitted from a material when it is exposed to light of a certain frequency or higher. This was first observed by Heinrich Hertz in 1887.

2. What is the difference between green and indigo light in the photoelectric effect?

In the photoelectric effect, the frequency of light is the determining factor for whether electrons will be emitted from a material. Green light has a lower frequency than indigo light, so it will require less energy for electrons to be emitted from the material.

3. How does the intensity of light affect the photoelectric effect?

The intensity of light does not affect the photoelectric effect. The frequency of light is the only factor that determines whether electrons will be emitted from a material.

4. What is the work function in the photoelectric effect?

The work function is the minimum amount of energy needed to remove an electron from a material. It varies for different materials and is dependent on the frequency of light being used.

5. What is the significance of the photoelectric effect?

The photoelectric effect has many practical applications, such as in solar panels, photodiodes, and photocells. It also played a crucial role in the development of quantum mechanics and our understanding of the nature of light.

Similar threads

  • Introductory Physics Homework Help
2
Replies
35
Views
2K
Replies
5
Views
876
  • Classical Physics
Replies
4
Views
766
Replies
5
Views
2K
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Electromagnetism
Replies
1
Views
1K
  • Quantum Physics
Replies
1
Views
982
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
3K
Back
Top