Difference in energy between potential and light in photoelectric effect

[Denver Dang]

Hi...

I have a quick question I'm not quite understanding.

If I shine some light on a surface, metal or something, and the energy of the incoming wave is larger than the energy-barrier for the electron on the surface, an electron will be emitted.
But my question is, if the incoming photon has the energy of, let's say, 1 ev, and the energy barrier is 0.5 ev, then the light will have twice the amount of energy it needs to emit the electron from the surface. But what happens with the rest then ?

If the barrier is 1.1 ev, nothing will happen, and the photon will just pass through or diffract, right ?
But in this case, will the electron absorb 0.5 ev from the photon, and the re-emit another photon with a changed wavelength that is equal to the left over energy of 0.5 ev ?


Thanks in advance.


Regards

 

[soulhunter]

The electron will leave the atom with 0.5 ev of kinectic energy and this electron now become a free electron and this kinectic energy will become heat like the electron moveing in metal.

 

[Denver Dang]

So the electron just get the energy from the photon, minus the work function of the electron, in kinetic energy ?

 

[soulhunter]

the left energy will become the kinectic energy of electron

 

[sardar]

,
Hello,

Thank you for your question about the difference in energy between potential and light in the photoelectric effect. The photoelectric effect is a phenomenon in which electrons are emitted from a material when it is exposed to light of a certain frequency or energy. This effect is important in understanding the behavior of light and electrons, and has been extensively studied by scientists.

To answer your question, let's first discuss the concept of energy levels in atoms and materials. Electrons in an atom or material can only exist at certain energy levels, and they can move between these levels by absorbing or emitting energy in the form of photons. The energy barrier you mentioned in your question is the minimum energy required for an electron to overcome the attraction of the positively charged nucleus and be emitted from the material.

In the case of your example, if the incoming photon has an energy of 1 ev and the barrier is 0.5 ev, the excess energy of 0.5 ev will be absorbed by the electron as kinetic energy. This means that the electron will be emitted with a velocity that is determined by this kinetic energy. The remaining energy of the photon will not be emitted as another photon, but will be lost as heat.

If the barrier is higher than the energy of the incoming photon, as in your example of a 1.1 ev barrier, the photon will not have enough energy to overcome the barrier and will either be reflected or transmitted through the material. In this case, the electron will not be emitted and the photon will not be absorbed.

In summary, the energy of the incoming photon must be equal to or greater than the energy barrier in order for the electron to be emitted. Any excess energy of the photon will be absorbed as kinetic energy by the electron, and the remaining energy will be lost as heat.

I hope this helps clarify the concept for you. If you have any further questions, please don't hesitate to ask.

Best regards,