Work Functions


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Ashley Chipoletti 1I
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Joined: Fri Sep 29, 2017 7:04 am

Work Functions

Postby Ashley Chipoletti 1I » Wed Oct 11, 2017 4:40 pm

What does the work function of a metal mean and imply for photoelectric effect?

Ethan-Van To Dis2L
Posts: 50
Joined: Fri Sep 29, 2017 7:05 am

Re: Work Functions

Postby Ethan-Van To Dis2L » Wed Oct 11, 2017 4:48 pm

The work function refers to the amount of energy needed to eject the electron from the metal which is also known as the threshold energy.
So the energy of the incoming photon (E=hv) - work function = kinetic energy of the electron

Vivian Nguyen
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Re: Work Functions

Postby Vivian Nguyen » Wed Oct 11, 2017 4:48 pm

Hello Ashley,

The work function is the energy necessary to eject an electron off of a specific type of metal (Copper, Aluminum, Zinc, etc...they all have different work functions). The work function can also be called the threshold energy and can also be signified with the greek letter phi . In terms of the photoelectric experiment, the electron cannot be ejected unless the specific threshold energy is met. Therefore, the Energy of the photon must at least be equal to the work function.

hope this helps!

Adrian Lim 1G
Posts: 88
Joined: Fri Sep 29, 2017 7:03 am

Re: Work Functions

Postby Adrian Lim 1G » Thu Oct 12, 2017 12:37 am

Just to clarify the above response - the energy of the incoming photon - work function = energy of the electron being ejected. Also remember that photons work in packets, meaning one photon needs to have a sufficient amount of energy to eject one electron, also known as the work function. One photon interacts with one electron.

Emma Boyles 1L
Posts: 19
Joined: Thu Jul 27, 2017 3:00 am

Re: Work Functions

Postby Emma Boyles 1L » Thu Oct 12, 2017 12:47 am

The equation you can use in this case:

E(photon) - work function = kinetic energy of ejected electron

hv - Φ = (1/2)mv^2

(planck's constant x frequency) - (threshold energy) = ((1/2) mass of electron x velocity of electron^2)


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