Work Function

[Ashley Johnson 2G]

I ama bit confused about the work function. In my notes I wrote that the work function is equal to the equation (E=h*v). E=h*v gives us E per photon. In another part of my notes, I have the equation E(photo)=work function + kinetic energy. If a question were to ask for the work function without giving us the kinetic energy, would we just use the E=h*v equation?

[VeronicaShepherd3B]

Hello when using the work function I would use the second equation. The first one is for the speed of light.

[Ashley Johnson 2G]

Hello when using the work function I would use the second equation. The first one is for the speed of light.

The speed of light equation is c=wavelength times frequency, the one I wrote is for energy of a photon.

[Matthew Li 1B]

if the photoelectric experiment does not eject an electron with kinetic energy, we would use E total = work function. Thus, we would use E=hv

[Sarah3C]

How do you calculate the work function? What equation/information is needed in order to find the value?

[Edwin Montalvo 1G]

We would need to use the second equation. We cannot ourselves derive/create the work equation, but we can use E(photo)=work function + kinetic energy to find the work function value. As you can see, if the emitted electron has no kinetic energy, then we know that the energy of the photon = the work function, which then means that the work function = E = hv. Hope this helps!

[105605391]

Also, I think it's helpful to view the work function as the threshold energy for the problems we are working on and realize that we can find E(work) using a variety of the formulas given as many can be connected to each other.

[Sunny Xiao 1A]

Yes, if the question does not give you the threshold energy/work function, (a) you would either not be able to calculate the Ephoton in the case that the question maintains there are ejected electrons, or (b) no electrons are ejected and Ephoton = work function.