Page 1 of 1

The Work Function

Posted: Fri Oct 18, 2019 4:54 pm
by Brittney Hun 2C
E=hv is also equal to the work function. What exactly is the work function and is it the threshold energy for the electron or for an element?

Re: The Work Function

Posted: Fri Oct 18, 2019 5:00 pm
by Aiden Metzner 2C
The work function is the energy it takes to expel an electron from a certain metal. The energy of the photon is E=hv and if you subtract the work function from that energy then the difference is the kinetic energy of the electron which is E=MV.

Re: The Work Function

Posted: Fri Oct 18, 2019 5:01 pm
by claudia_1h
The work function is the energy required to remove an electron from a metal. Each type of metal has a specific work function. Think of it as the threshold energy or minimum energy to remove the electron. When you say E=hv is equal to work function, I think you may be referring to how the kinetic energy of the electron is equal to hv (the energy supplied by a photon) - the work function.

Re: The Work Function

Posted: Fri Oct 18, 2019 7:01 pm
by Arianna Perea 3H
does the metal eject electron if the energy and work function are the same?

Re: The Work Function

Posted: Sun Oct 20, 2019 11:15 am
by Nare Arakelian Dis 3E
Is the work function the same as the ionization energy then?

Re: The Work Function

Posted: Sun Oct 20, 2019 11:22 am
by Izzie Capra 2E
Nare Arakelian Dis 3E wrote:Is the work function the same as the ionization energy then?


No, work function is the energy required to remove an electron from a solid, like the metals we have been talking about in lecture. The ionization energy is the energy required to move an electron from an atom in the gas phase.

Re: The Work Function

Posted: Sun Oct 20, 2019 8:25 pm
by Kimme Chun 1I
The work function and threshold energy is the least amount of energy needed to eject an electron from a metal.

Re: The Work Function

Posted: Sun Oct 20, 2019 8:36 pm
by Robert Cross 1A
I agree with everything posted so far, but I think for clarification it should be noted that the work function of a particular metal is not dependent on the intensity of the light, but rather the individual energy of each photon. Essentially, an electron can only be emitted from the metal if the energy of an individual photon is high enough to eject it. Because of this, there is a minimum energy requirement to eject an electron, the ejection of electrons is dependent on the frequency (energy) of the photon, rather than the quantity of photons an electron may interact with.

Re: The Work Function

Posted: Sun Oct 20, 2019 9:43 pm
by Naomi 3G
Could someone explain to be how you use the work function to find kinetic energy of an electron and the energy needed to remove an electron. Specifically in the case of these two questions from the video module assessments.
"Light hits a sodium metal surface and the velocity of the ejected electron in 6.61*10^5 ms^-1. The work function for sodium is 150.6kJmol-1."
What is the kinetic energy of the ejected electron?
How much energy is required to remove an electron from one sodium atom?

Re: The Work Function

Posted: Sun Oct 20, 2019 9:47 pm
by kpang_4H
Naomi 3G wrote:Could someone explain to be how you use the work function to find kinetic energy of an electron and the energy needed to remove an electron. Specifically in the case of these two questions from the video module assessments.
"Light hits a sodium metal surface and the velocity of the ejected electron in 6.61*10^5 ms^-1. The work function for sodium is 150.6kJmol-1."
What is the kinetic energy of the ejected electron?
How much energy is required to remove an electron from one sodium atom?


The work function tells you how much energy is required to remove an electron from on sodium atom, and the kinetic energy of the ejected electron can found by using KE= .5(mass of electron)(velocity)

Re: The Work Function

Posted: Sun Oct 20, 2019 9:48 pm
by kpang_4H
Arianna Perea 3H wrote:does the metal eject electron if the energy and work function are the same?


As long as the energy of the photon is greater or equal to the work function, the metal will eject the electron. Any excess energy is regarded as kinetic energy.

Re: The Work Function

Posted: Sun Oct 20, 2019 9:49 pm
by Kaylee Clarke 1G
the work function is the representation of the energy it takes to eject electrons from a metal and it is found with the equation E=hv.

Re: The Work Function

Posted: Sun Oct 20, 2019 10:16 pm
by Sean Sugai 4E
The work function is the energy required to remove an electron from a metal, which means that the work function is not constant and changes depending on the metal used. In addition, the kinetic energy of an ejected electron is equal to the difference between the energy from the photon and the work function. If the energy from the photon is less than or equal to the work function, then an electron will not be ejected, regardless of the intensity of the light. Conversely, if the energy of the photon is greater than the work function, then an electron is ejected and can be computed using the kinetic energy equation: 1/2mv^2.

Re: The Work Function

Posted: Sun Oct 20, 2019 10:34 pm
by Elizabeth Johnson 1I
Nare Arakelian Dis 3E wrote:Is the work function the same as the ionization energy then?

bruh what is ionization energy

Re: The Work Function

Posted: Sun Oct 20, 2019 10:35 pm
by Elizabeth Johnson 1I
Izzie Capra 4D wrote:
Nare Arakelian Dis 3E wrote:Is the work function the same as the ionization energy then?


No, work function is the energy required to remove an electron from a solid, like the metals we have been talking about in lecture. The ionization energy is the energy required to move an electron from an atom in the gas phase.


oop there's the answer

Re: The Work Function

Posted: Mon Oct 21, 2019 12:21 pm
by Keerthana Sivathasan 2E
E=hv is not equal to the work function, but E(kinetic)=hv-(work function) is the equation you should use for the photoelectric effect. Hv is the energy of the photon coming in and shining on the metal, work function is the energy it takes for an electron to be emitted off a specific metal, and kinetic energy is the excess energy that the electron can leave with if hf-(work function) is more than 0.