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Jimmy Moriaty
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Please tell me,why can't a photon transfer it's energy completely to a free electron?
Orodruin said:This would necessarily violate the conservation of momentum.
But in the photo-electric effect it's happeing.why?Orodruin said:This would necessarily violate the conservation of momentum.
Momentum is being transferred to something else and therefore it is conserved overall.Jimmy Moriaty said:But in the photo-electric effect it's happeing.why?
Then,why can't electron travel the same direction which the photon have been travelled?Drakkith said:So what happens when the electron absorbs the photon?
Then, why can't electron travel the same direction which the photon have been travelled?(after absorbing the energy of photon)Orodruin said:Momentum is being transferred to something else and therefore it is conserved overall.
Jimmy Moriaty said:Then,why can't electron travel the same direction which the photon have been travelled?
(after absorbing the energy of photon)
Jimmy Moriaty said:Then,why can't electron travel the same direction which the photon have been travelled?
(after absorbing the energy of photon)
Then, why can't electron travel the same direction which the photon have been travelled?(after absorbing the energy of photon)
Jimmy Moriaty said:Then, why can't electron travel the same direction which the photon have been travelled?(after absorbing the energy of photon)
Yeah!Nugatory said:Try it... The electron changes its speed from 0 to ##v## as it absorbs the photon. The kinetic energy of the (non-relativistic, for simplicity) electron increases from zero to ##mv^2/2## and the momentum from 0 to ##mv##. If the photon is to be completely absorbed and energy and momentum are to be conserved, then these values must be equal to the energy ##p_{\gamma}c## and the momentum ##p_{\gamma}## of the initial photon. A bit of algebra will pretty quickly convince you that this isn't possible - if the increase in the electron's energy is equal to the photon's total energy then the momentum won't balance, and vice versa.
Jimmy Moriaty said:But what's the wrong in this assumption?
The reason is that the mass of the electron is fixed. If the electron could become more massive then it would be possible to conserve both the energy and the momentum of the collision. This is why a free atom can absorb a photon but not a free electron.Jimmy Moriaty said:But what's the reason for this?
That's quite relativistic values. Just for an advice for a more accurate verification is to use relativistic formula, upon which you should find that ## \hbar \omega + m_ec^2 = \sqrt{(\hbar \omega)^2 + (m_ec^2)^2}## and you see the discrepancy very clearly. As Dale has said, this equation can be satisfied if ##m_e## on the RHS is allowed to increase.Jimmy Moriaty said:I've chose the wavelength of 0.071nm x-rays.
When I consider the E=Pc & P=mv I've got v=1.025*10^7 ms^-1
But when i chose E=Pc & E=1/2 mv^2 it's v=7.84*10^7 ms^-1
But what's the reason for this?
Jimmy Moriaty said:But in the photo-electric effect it's happeing.why?
drl said:If a photon can give a packet of energy to an electron, overcoming its work function and freeing it up, can a low energy photon recover that same packet and cause the electron to revert to its bound state?
I am assuming that an electron and an atom exist in particle form in their bound state and in a wave form in their free state.
drl said:Bohr said that they can only exist separately and what I've read most physicists seem to agree.
Drakkith said:Not sure. That almost sounds like stimulated emission, but that process doesn't involve light of different wavelengths.
That would be incorrect. There aren't two separate states that objects transition between. They always behave according to their fundamental properties, some of which are 'wave-like' and some of which are 'particle-like'.
You've been victimized by the pop-sci explanations of quantum mechanics. Bohr actually said something subtly different: you can design and execute experiments that show wave-like behavior, and you can design and execute experiments that show particle-like behavior, but you cannot design a single experiment that shows both at the same time.drl said:Bohr said that they can only exist separately and what I've read most physicists seem to agree.
drl said:I believe that Bohr said that that wave and particle form cannot exist at the same time.The reason I asked about the exchange of energy between the electron (in its free or wave state ) and a low energy photon recovering the energy packet which overcame the electromagnetic attraction to an atom (work function) this would return the electron to its bound particle form from its free wave form.
drl said:Add to this the assumption that when light,electrons or atoms approach the 2 slits they are in their free wave forms or they would still be in a bound particle state.i.e. when a particle leaves its bound state it is converted to a free wave state. Got it? The ability to revert back and forth as a result of transfer of energy packet equivalent to the work function could solve a lot of problems in the 2 slit experiment.
Energy transfer from photon to an electron is a process in which a photon, which is a particle of light, transfers its energy to an electron, causing the electron to become excited and move to a higher energy state.
Energy transfer from photon to an electron occurs through a process called photoelectric effect. When a photon collides with an electron, it transfers its energy to the electron, causing it to be ejected from its atom.
The energy transfer from photon to an electron is affected by the energy of the photon, the properties of the material the electron is in, and the distance between the photon and the electron.
Energy transfer from photon to an electron is used in various technologies, such as solar cells and photodiodes. In solar cells, the energy transfer is used to convert sunlight into electricity, while in photodiodes, it is used to detect light and convert it into electrical signals.
No, energy transfer from photon to an electron is not a reversible process. Once the electron has absorbed the energy from the photon, it cannot be returned to its original state and the energy is lost. However, the electron can release the energy through other processes such as emitting light or heat.