What are Einstein's 3 postulates for Photo electric effect?

In summary, the photoelectric effect can be explained by quantum physics through certain conclusions: photoelectrons are only emitted if the frequency of the photon is greater than the threshold frequency and the energy of the photon is greater than the work function. Increasing the intensity of light only increases the number of photons and photoelectrons, not the kinetic energy. The three postulates proposed by Einstein include the concept of discrete energy packets for electrons, which was originally postulated by Max Planck. More information can be found by researching the history of quantum mechanics.
  • #1
uzman1243
80
1
There are certain conclusions that can be explained by quantum physics about the photoelectric effect:
1) photoelectrons only emitted if frequency>threshold frequency and hence energy of photon> work function
2)Increasing intensity increases no. of photons (and thus photoelectrons provided f>f0 ) and NOT the kinetic energy

But what are the actual postulates (3) proposed by Einstein?
Something like electron discrete energy packets (i'm not really sure).
Can you help me out
 
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  • #2
The discrete energy packets where as far as I know originally postulated by Max Planck who found a equation that discribes the black body radiation after Wien and ralley jeans law where thought of. But Einstein cirtenly did work on energy levels, I do not doubt that.
 
  • #3

1. What are Einstein's three postulates for the photoelectric effect?

Einstein's three postulates for the photoelectric effect are:

  • The energy of a photon is proportional to its frequency.
  • The photoelectric effect only occurs if the frequency of the incident light is above a certain threshold.
  • The number of electrons emitted is proportional to the intensity of the incident light, but not its frequency.

2. How do these postulates explain the photoelectric effect?

Einstein's postulates explain the photoelectric effect by showing that light behaves as both a particle and a wave. The first postulate states that the energy of a photon is directly related to its frequency, which explains why higher frequency light (such as ultraviolet) can cause electrons to be emitted from a material. The second postulate explains the threshold frequency, as only photons with enough energy can cause the photoelectric effect. The third postulate explains the relationship between the intensity of light and the number of electrons emitted.

3. What is the significance of Einstein's postulates for the field of physics?

Einstein's postulates for the photoelectric effect were significant because they helped to reconcile the wave and particle nature of light. They also provided evidence for the concept of quantization, which suggests that energy can only exist in discrete packets. This was a major breakthrough in understanding the behavior of light and paved the way for further discoveries in quantum mechanics.

4. How were Einstein's postulates for the photoelectric effect tested?

Einstein's postulates were tested through various experiments, including those conducted by Robert Millikan and Arthur Compton. These experiments involved shining different frequencies of light onto a metal surface and measuring the number and energy of electrons emitted. The results of these experiments confirmed Einstein's postulates and provided evidence for the particle nature of light.

5. Are Einstein's postulates still relevant in modern physics?

Yes, Einstein's postulates for the photoelectric effect are still relevant in modern physics. They have been incorporated into the quantum theory of light and continue to be used in the study of the photoelectric effect. Additionally, these postulates have had a significant impact on our understanding of the nature of light and its behavior, which is still a major focus of research in physics today.

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