Photoelectric Effect Question
'Explain why the emitted electrons have a range of kinetic energies up to a maximum value'
I just don't get it
I just don't get it
Original post by 3607
'Explain why the emitted electrons have a range of kinetic energies up to a maximum value'
I just don't get it
I just don't get it
Hard to give a hint really, so I'll just tell you what my teacher told me:
Spoiler
The work function is the minimum energy required for photoelectric emission. When individual photons of monochromatic light with energy E=hf interact with individual electrons they transfer all their energy . Those electrons that are held least tightly only require enough energy to overcome the work function to escape and as a result leave with maximum kinetic energy remaining. Some electrons are held more tightly and must use more energy in emission resulting in smaller values for their kinetic energy.
Original post by 3607
So stuff deeper in needs more energy to release it?
essentially yes, another reason is that the dipoles in the metal change orientation rapidly and so some electrons will experience a stronger pull from the metal and require more energy to eject - the work function of the metal is the absolute minimum required for a photoelectron to be ejected.
Original post by 3607
'Explain why the emitted electrons have a range of kinetic energies up to a maximum value'
I just don't get it
I just don't get it
For the emission of electrons the work function of the metal needs to be overcome. Once the electron has gained sufficient energy, either by interaction with another electron or by absorbing a photon, the electron is excited. Electrons which have lots of energy use some of the energy as kinetic energy. If an electron is being removed from deeper within the metal, it will have less kinetic energy because more work is done to push the electron to the surface of the metal, from where it can be emitted. Electrons that are on the surface of the metal will have more energy because they don't use any of their energy to push their way through the metal because they are already on the surface.
Therefore electrons can have a range of kinetic energies.
Hope that helped!
Original post by Nav_Mallhi
Once the electron has gained sufficient energy, either by interaction with another electron or by absorbing a photon, the electron is excited.
Don't get confused between excitation and the photoelectric effect.
Original post by usycool1
Don't get confused between excitation and the photoelectric effect.
I know the difference but excitation is a part of the photoelectric effect right? The electrons have to be excited in order to the emission of electrons to occur. Am I right?
Original post by Nav_Mallhi
I know the difference but excitation is a part of the photoelectric effect right? The electrons have to be excited in order to the emission of electrons to occur. Am I right?
The photoelectric effect can only happen if photons with sufficient energy are absorbed by electrons in the metal. It doesn't really have anything to do with electron collision or interaction, as you said in your previous post.
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