Threshold Frequency: Find Energy of Photoelectron w/ 0.4eV Work Function

AI Thread Summary
To find the threshold frequency for the liberation of photoelectrons from a material with a work function of 0.4 eV, the energy of a single photon must equal the work function. The relevant equation is K.E = hf - work function, which simplifies to hf = work function at threshold frequency. Therefore, the threshold frequency can be calculated using the equation f = work function / h, where h is Planck's constant. The energy of the photon at this frequency will be exactly 0.4 eV, sufficient to release photoelectrons. Understanding this relationship is crucial for applying the photoelectric effect in practical scenarios.
jazzchan
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Dear all

The question is :
A certain material has a work function of 0.4eV. What is the energy of a single photon of electromagnetic radiation at the threshold frequency for liberation of photoelectrons?

Would u give me some hint how to find the threshold frequency at first ??

thanks all

jazz
 
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Hint : Photoelectric Eqn
 
can i assume the equation is:
K.E = hf - work function = 0 ??

thanks
 
Right. At the threshold frequency the photons have an energy just equal to the work function.
 
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