## Work function or incoming light

Natalie Phan 3G
Posts: 35
Joined: Wed Sep 30, 2020 9:48 pm

### Work function or incoming light

When a problem asks to find the energy required to remove an electron, is it asking for the work function or the incoming light? What about the energy that caused photoejection of an electron? I've just seen it come up a few times in homework problems so I wanted to clarify which was referring to which.

Posts: 84
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### Re: Work function or incoming light

The energy required to remove an electron is the work function because you could have incoming light with greater energy than is required to remove the electron, which would then give you an ejected electron with kinetic energy (think about the equation E(photon)-work function= KE). The energy that caused ejection of an electron is most likely the energy of the incoming light because the work function is not actually causing anything, it is merely the threshold energy that needs to be surpassed for the electron to be ejected.

Hope this helps!

Allan Nguyen 2E
Posts: 42
Joined: Wed Sep 30, 2020 9:49 pm

### Re: Work function or incoming light

When the problem asks to find the energy to remove an electron, that would be considered the work function or threshold energy. If a problem asks for the energy that causes the photoejection of an electron, that would be the incoming light or incident light.

Eunice_Castro_1G
Posts: 62
Joined: Wed Sep 30, 2020 9:46 pm

### Re: Work function or incoming light

When the problem is asking for the energy to remove it is talking about the threshold energy. Hope this helps!

Natalie Phan 3G
Posts: 35
Joined: Wed Sep 30, 2020 9:48 pm

### Re: Work function or incoming light

Stuti Pradhan 1B wrote:The energy required to remove an electron is the work function because you could have incoming light with greater energy than is required to remove the electron, which would then give you an ejected electron with kinetic energy (think about the equation E(photon)-work function= KE). The energy that caused ejection of an electron is most likely the energy of the incoming light because the work function is not actually causing anything, it is merely the threshold energy that needs to be surpassed for the electron to be ejected.

Hope this helps!

This makes so much sense! Thank you for answering my question and explaining so thoroughly!

Ariel Guan 1G
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### Re: Work function or incoming light

energy required to remove an electron is the work function, and the energy that caused photoejection is the energy of the incoming light

Kiara Phillips 1L
Posts: 38
Joined: Wed Sep 30, 2020 10:04 pm

### Re: Work function or incoming light

In this case they would be asking you to find the work function/threshold energy.