## The Work Function

Brittney Hun 2C
Posts: 104
Joined: Wed Sep 11, 2019 12:15 am

### The Work Function

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?

Aiden Metzner 2C
Posts: 104
Joined: Wed Sep 18, 2019 12:21 am

### Re: The Work Function

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.

claudia_1h
Posts: 111
Joined: Fri Aug 09, 2019 12:16 am

### Re: The Work Function

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.

Arianna Perea 3H
Posts: 50
Joined: Thu Jul 25, 2019 12:17 am

### Re: The Work Function

does the metal eject electron if the energy and work function are the same?

Nare Arakelian Dis 3E
Posts: 58
Joined: Thu Jul 11, 2019 12:16 am

### Re: The Work Function

Is the work function the same as the ionization energy then?

Izzie Capra 2E
Posts: 103
Joined: Sat Sep 07, 2019 12:19 am

### Re: The Work Function

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.

Kimme Chun 1I
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Joined: Sat Sep 07, 2019 12:17 am
Been upvoted: 1 time

### Re: The Work Function

The work function and threshold energy is the least amount of energy needed to eject an electron from a metal.

Robert Cross 1A
Posts: 35
Joined: Wed Sep 11, 2019 12:15 am

### Re: The Work Function

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.

Naomi 3G
Posts: 9
Joined: Wed Sep 18, 2019 12:20 am

### Re: The Work Function

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?

kpang_4H
Posts: 55
Joined: Fri Sep 20, 2019 12:17 am

### Re: The Work Function

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)

kpang_4H
Posts: 55
Joined: Fri Sep 20, 2019 12:17 am

### Re: The Work Function

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.

Kaylee Clarke 1G
Posts: 103
Joined: Fri Aug 30, 2019 12:15 am

### Re: The Work Function

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.

Sean Sugai 4E
Posts: 56
Joined: Wed Sep 11, 2019 12:17 am

### Re: The Work Function

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.

Elizabeth Johnson 1I
Posts: 53
Joined: Wed Sep 11, 2019 12:16 am

### Re: The Work Function

Nare Arakelian Dis 3E wrote:Is the work function the same as the ionization energy then?

bruh what is ionization energy

Elizabeth Johnson 1I
Posts: 53
Joined: Wed Sep 11, 2019 12:16 am

### Re: The Work Function

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.

Keerthana Sivathasan 2E
Posts: 101
Joined: Wed Sep 18, 2019 12:22 am

### Re: The Work Function

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.