## Threshold Energy [ENDORSED]

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Priscilla Okaiteye
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### Threshold Energy

I know this was covered in lecture but I'm still a bit confused. What exactly is the threshold energy and how does it relate to quantum equations?

Vivian Gonzalez 1A
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### Re: Threshold Energy  [ENDORSED]

Threshold energy is the amount of energy needed to eject an electron from a metal.

Neha Divi 1K
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### Re: Threshold Energy

To add on, the photoelectric effect is the idea that there is an ejection of electrons from a metal when its surface is exposed to ultraviolet radiation. Furthermore, no electrons are ejected unless the radiation has a frequency above a certain threshold that is characteristic of a metal.

Jada Larson 1F
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### Re: Threshold Energy

The equation related to threshold energy is:
Ephoton - Erequired to eject electron = Eexcess

Ephoton=hv. [*]h = 6.626 x 10-34 Js and [*]the v is frequency
Erequired to eject electron is called the threshold energy or the work function, and it is represented by the symbol ϕ.
Eexcess equals EK = (1/2)mv2. [*]note: the v is for velocity, not frequency

Cameron Smith 1I
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### Re: Threshold Energy

What occurs to the kinetic energy that is the excess when the energy of the photon is greater than the threshold energy?

Alma Flores 1D
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### Re: Threshold Energy

In Friday's lecture, Dr. Lavelle mentioned that the energy of of the photon is equal to the sum of the threshold energy and the kinetic energy.

Sonia Aronson 1B
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### Re: Threshold Energy

The threshold energy is the minimum amount of energy required to move an electron from the surface of a metal.

Isobel Tweedt 1E
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### Re: Threshold Energy

How does this relate to the concept of darkness versus lightness? Does the release of electrons result in our viewing of light and the color spectrum?

004985802
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### Re: Threshold Energy

it is the energy required to move an electron from one state (energy level) to the next. If the input energy is less than threshold, the electron will remain at the same state (energy level).

breannasung_1K
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### Re: Threshold Energy

Threshold energy is the amount of energy needed to remove an electron from the metal.

AnnaYan_1l
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### Re: Threshold Energy

Cameron Smith 1I wrote:What occurs to the kinetic energy that is the excess when the energy of the photon is greater than the threshold energy?

I believe that in the photoelectric experiment, this kinetic energy is detected by a detector which shows the excess energy of the photon that surpassed the threshold energy (since kinetic energy = energy of the photon - threshold energy (also known as work function)).

NabilaNizam-1K
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### Re: Threshold Energy

What affects the threshold energy of a photon?

Caroline Crotty 1D
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### Re: Threshold Energy

A threshold energy is specifically effected by what metal you are attempting to eject an electron from. Think of threshold energy almost as ionization energy, each metal will have its own specific threshold energy to have a single electron ejected.

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