Units of the Work Function

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Pranav Kadiyala 1A
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Units of the Work Function

Postby Pranav Kadiyala 1A » Mon Oct 19, 2020 10:35 am

If we are asked to the find the work function / threshold energy of a certain element, do we give it in energy per electron, or energy per mole of electrons?

Brittney Nguyen 2L
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Re: Units of the Work Function

Postby Brittney Nguyen 2L » Mon Oct 19, 2020 10:38 am

At the proper frequency, one photon will eject one electron, so we give answers in terms of energy per electron. The question will often specify if it wants the answer in energy per mole of electron.

Megan Sparrow 1A
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Re: Units of the Work Function

Postby Megan Sparrow 1A » Mon Oct 19, 2020 10:40 am

I believe it is just per electron. The official definition of the work function is "the minimum quantity of energy which is required to remove an electron to infinity from the surface of a given solid, usually a metal." In addition, when solving problems where you have to find the total amount of electrons given the total energy and work function, you divide total energy by the work function. This helps explain why I believe it is per electron.

Alara Aygen 3K
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Re: Units of the Work Function

Postby Alara Aygen 3K » Mon Oct 19, 2020 10:41 am

I believe it is energy per electron. You might need to convert it to moles if the question specifically asks you to do so.

Abby Lam 3F
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Re: Units of the Work Function

Postby Abby Lam 3F » Mon Oct 19, 2020 11:08 am

I think energy per electron unless specified.

905290504
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Re: Units of the Work Function

Postby 905290504 » Mon Oct 19, 2020 12:38 pm

the work function tells you how much energy is needed to remove ONE electron, so the units should reflect that. I wouldn't be surprised though if the midterm asked for the answer in joules/mole or something, but you would just do the calculations as normal unitl the end when youd make the conversion with Avogadro's number

Darlene Lien 3E
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Re: Units of the Work Function

Postby Darlene Lien 3E » Mon Oct 19, 2020 12:46 pm

As with what the others said, the units of the work function should be Joules (or Joules per electron), but if you are asked in terms of moles then you would most likely have to use Avogradro's number accordingly. Hope this helps!

Gabriel Nitro 1E
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Re: Units of the Work Function

Postby Gabriel Nitro 1E » Mon Oct 19, 2020 1:05 pm

Hi,

It depends on the problem, but in most cases we will be working with energy in terms of one particle (i.e. photons or electrons as in the photoelectric experiment).

Hope this helps! :)


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