When energy is equal to work function

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Alvaro Chumpitaz 4D
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When energy is equal to work function

Postby Alvaro Chumpitaz 4D » Wed Oct 16, 2019 10:06 pm

So in the photoelectric effect, what would happen if the energy of the photon is equal to that of the work function (ie no KINETIC ENERGY)?

ishaa Diwakar 4E
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Re: When energy is equal to work function

Postby ishaa Diwakar 4E » Wed Oct 16, 2019 10:10 pm

If the energy is equal to the work function, the electron would not be ejected from the metal, therefore it would have 0 kinetic energy.

Ryan Narisma 4G
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Re: When energy is equal to work function

Postby Ryan Narisma 4G » Wed Oct 16, 2019 10:54 pm

Hi Alvaro Chumpitaz 4D! I respectfully disagree with ishaa Diwakar 4E and the comment that "the electron would not be ejected from the metal". If the Energy of the photon of incoming light is EQUAL to the work function (Energy THRESHOLD) then the ELECTRON WILL BE EJECTED. This is true because of the data gathered in the photoelectric experiment. In the experimental design, the detector that notes whether electrons are ejected from the metal has a positive charge to it which will attract the ejected electrons EVEN IF there is NO KINETIC ENERGY. Energy THRESHOLD (work function) is the MINIMUM energy required to EJECT the electron. So, the electron WILL BE EJECTED if E-photon = E-threshold.

Sartaj Bal 1J
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Joined: Thu Jul 25, 2019 12:17 am

Re: When energy is equal to work function

Postby Sartaj Bal 1J » Thu Oct 17, 2019 12:54 am

The key observation in worked out photoelectric effect problems is that when an ejected electron has 0 kinetic energy, the energy of the photon is equal to the energy required to remove the electron. The example in lecture based off this premise asked what could be the longest wavelength light to accomplish this and the threshold energy value is used for the "E" in the equation.

005321227
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Re: When energy is equal to work function

Postby 005321227 » Fri Oct 18, 2019 11:38 am

when the energy of the photon of the energy required to eject the electron from the metal, the electron will be ejected from the metal!

Qilan Li 4I
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Re: When energy is equal to work function

Postby Qilan Li 4I » Sun Oct 20, 2019 1:02 pm

If the energy of the photon is equal to that of the work function, it means that the energy threshold will be met and the electron will be ejected.

PGao_1B
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Re: When energy is equal to work function

Postby PGao_1B » Sun Oct 20, 2019 2:32 pm

In the photoelectric effect, if the energy of the photon is equal to that of the work function (i.e. no kinetic energy), what would happen is that the energy threshold will be met and the electron will be ejected.

Adelpha Chan 1B
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Re: When energy is equal to work function

Postby Adelpha Chan 1B » Tue Oct 22, 2019 3:10 pm

Alvaro Chumpitaz 4D wrote:So in the photoelectric effect, what would happen if the energy of the photon is equal to that of the work function (ie no KINETIC ENERGY)?


No additional kinetic energy means that the only output from the metal is the ejected photon. There is no additional kinetic energy resulting from the light source hitting the solid metal.

Viviana Velasquez
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Re: When energy is equal to work function

Postby Viviana Velasquez » Wed Oct 30, 2019 2:30 am

When the energy of the photon is equal to the work function, the electron will be ejected. However, there will no excess energy (kinetic energy).

ASetlur_1G
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Re: When energy is equal to work function

Postby ASetlur_1G » Sun Nov 03, 2019 9:20 pm

When the energy of the photon is exactly equal to the work function, the kinetic energy is 0, so the electron will still be ejected, but it won't be able to escape from the nucleus because the velocity is 0. Usually, if the energy of the photon is greater than the work function, the electron is ejected with some velocity.


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