Photoelectric Effect


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Suraj Doshi 2G
Posts: 100
Joined: Fri Aug 02, 2019 12:15 am

Photoelectric Effect

Postby Suraj Doshi 2G » Mon Oct 07, 2019 12:21 pm

I just wanted to clarify something:

In the photoelectric effect, is it true that only high-frequency light(as opposed to low-frequency light) has enough energy (within the photon) to eject an electron from the surface it interacts with?

sarahforman_Dis2I
Posts: 109
Joined: Sat Aug 17, 2019 12:18 am

Re: Photoelectric Effect

Postby sarahforman_Dis2I » Mon Oct 07, 2019 12:25 pm

Yes, that is correct. Before the experiment was done, it was predicted that regardless of the energy (or frequency) of the light, increasing the intensity (amplitude) of even low energy lights would cause an electron to be ejected. This was not the case. In reality, only high energy lights (high frequency) caused the ejection of electrons, and increasing the intensity of low energy lights did not.

JohnWalkiewicz2J
Posts: 103
Joined: Thu Jul 11, 2019 12:17 am
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Re: Photoelectric Effect

Postby JohnWalkiewicz2J » Mon Oct 07, 2019 12:34 pm

Hey!
From my understanding, light below a certain frequency threshold will not cause electrons to be emitted.
Light above the certain threshold frequency will always cause electrons to be emitted, and increasing the intensity of this light will cause more electrons to be admitted.
If by "high frequency" you mean above the frequency threshold, then yes you have a pretty good understanding of the Photoelectric Effect.

DMuth_1J
Posts: 63
Joined: Thu Jul 11, 2019 12:15 am

Re: Photoelectric Effect

Postby DMuth_1J » Tue Oct 08, 2019 11:28 am

It's important to realize that the terms "high" and "low" are relative to the metal by which the experiment is being performed on. The frequency must be high enough, or the wavelength short enough, to eject an electron from a metal surface based on the threshold energy. If the threshold energy is low, then the frequency may also be low. High frequency simply means higher (or equal to) the threshold energy.

Hannah Romano 4D
Posts: 55
Joined: Sat Aug 24, 2019 12:18 am

Re: Photoelectric Effect

Postby Hannah Romano 4D » Tue Oct 08, 2019 11:38 am

In the simplest terms, only high frequencies of light will eject electrons. However, because each type of metal has a unique electron configuration, the specific high frequency required to eject electrons is relative to the metal that is being struck by the light. It is best to consider the high frequency required to eject an electron as a unique THRESHOLD dependent on the type of metal.


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