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### Threshold Energy

Posted: Thu Oct 31, 2019 7:58 pm
What is the definition of threshold energy and how do we find it?

### Re: Threshold Energy

Posted: Thu Oct 31, 2019 8:25 pm
threshold energy is also called the work function. Remember in the photoelectric effect experiment, the incoming energy of electromagnetic radiation needed to reach a certain threshold energy, or threshold frequency, to be able to eject an electron. You can calculate this with the equation that states Threshold Energy = Energy of the incoming photon - KE.

### Re: Threshold Energy

Posted: Fri Nov 01, 2019 11:38 am
Threshold energy is the minimum amount of energy to eject an e- (from the photoelectric effect). If the incoming light has more than the threshold energy, the remaining energy is emitted as kinetic energy. Therefore, E(incoming light) = threshold energy + kinetic energy. Usually, the work function is given to you, but if it isn't you can solve for it by substituting kinetic energy as 0 (since no kinetic energy would be given off).