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We know that when a light of specific frequency is collided on the silicon metal plate electron released from it, this is the photoelectric effect

This effect proves the particle nature of light , but at the same time it also say that we need "specific frequency"

But frequency is the property of wave , so how do photoelectric effect prove particle nature of light?

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  • $\begingroup$ See this answer: physics.stackexchange.com/a/671013/247642 In a nutshell: The energy (density) of a classical electromagnetic wave is proportional to its intensity, i.e., the squared amplitude of the intensity, whereas in quantum theory all particles carry energy proportional to their frequency, $E=\hbar\Omega$. $\endgroup$
    – Roger V.
    Commented Jan 6, 2022 at 12:36
  • $\begingroup$ No my question is different $\endgroup$
    – user324098
    Commented Jan 7, 2022 at 12:41
  • $\begingroup$ It says that , frequncy is the property of wave , and photoelectric effect proves particle nature of light , but it also say that specific frequency require for photoelectric effect . So how can it proves that light contains particle , frequncy is not the property of particles. This is my question $\endgroup$
    – user324098
    Commented Jan 7, 2022 at 12:43

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The thing is that light is actually not consisting of particles, nor of waves. One should really think of light as consisting of "wave packages". It is sometimes best described as particles and sometimes as waves, but it is neither in general.

Looking then at the photoelectric effect: If light was a wave, then electrons would come of the metal plate at any frequency as long as the intensity of the light is high enough, but that does not happen! In reality, there is what is called a threshold frequency. Furthermore, if light was consisting of waves, it would take time for electrons to escape (in order to build up energy), but what is found is that there is no delay. The idea then of Einstein is that light comes in "pieces" (= wave packages). These packages are called photons and have a certain energy $E = h\nu$. This would explain the phenomena in the sense that if your light has a frequency that is too low, no electrons will escape. This is simply because the photon energy is too low and will thus not be absorbed, no matter how many photons there are (= no matter how high the intensity).

To summarize an answer to your question, frequency is is a property of the "wave package", which is called a photon.

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  • $\begingroup$ My question says that , frequncy is the property of wave , and photoelectric effect proves particle nature of light , but it also say that specific frequency require for photoelectric effect . So how can it proves that light contains particle , frequncy is not the property of particles. $\endgroup$
    – user324098
    Commented Jan 7, 2022 at 14:28
  • $\begingroup$ Frequency is a property of the wave packages! $\endgroup$
    – Polymers_physics_2000
    Commented Jan 7, 2022 at 15:32