Work function [ENDORSED]

[Priscilla Okaiteye]

I do not quite understand the purpose of the work function. Can someone please explain it to me? When would you use it? What type of questions would require you to use the work function?

[tatianatumbling_1J]

Work function is the amount of energy (joules) needed to emit an electron from a photon. Most of the time the work function is given in the problems BUT it is in eV (electrovolts) and you have to convert it to Joules- there is a conversion number you can google.

An example of a work function problem is "calculate the threshold energy given the lowest frequency photon". The work function is equal to the Energy of a Photon - the Kinetic Energy.You will first have to calculate the energy of a photon (E=h*frequency) and sometimes you will have to calculate the kinetic energy(1/2 * m*v^2) if they give you a velocity.

Hope this was helpful!

[Susu Le 1F]

The work function is used in the photoelectric effect problems. And just to clarify, the kinetic energy that is mentioned in the above answer is the kinetic energy of the electron that is emitted. Therefore, the energy of the photon (Ep) - the work function = the kinetic energy of the electron (Ek).

[Madison Hacker 1L]

Another thing to add, it is the energy required to eject an electron. So, if the energy supplied by the photon is less than the work function, it will not eject the electron.

[Liliana Rosales 1E]

Just to clarify, the work function would be the minimum energy required to take off an electron from the surface of a metal right?

[Chem_Mod]

Yes

[Sophie W]

Work function is the minimum energy required to remove an electron from the surface of a metal which is why you can find the energy of the photon released by subtracting the work function from the kinetic energy of the electron that shot off of the metal