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It means that electron has a charge - the photon interacts with those particles that have a charge because the photon is the messenger of the electromagnetic force that is excited by this charge. But because the "gauge group" behind electromagnetism is Abelian, the messenger - photon - is neutral itself. I knew electrons are negatively charge but how could something that's not charged be attracted to something that is charged?
Negative attracts positive. The interaction is more complicated. Add a comment. Active Oldest Votes. Absorption and attraction are two different things. Improve this answer. Thank you! Dan Dan 5, 3 3 gold badges 29 29 silver badges 51 51 bronze badges. Light does affect electrons, but that's not what electric charge is. The kinetic energy of an emitted electron varies directly with the frequency of the incident light.
If the experimental values of these energies are fitted to a line, the slope of that line is Planck's constant. The principle of conservation of energy dictates that the energy of a photon must all go somewhere. The results from a photoelectric experiment are shown in Figure 2. The solid lines represent the actual observed kinetic energies of released electrons. The dotted red line shows how a linear result can be obtained by tracing back to the y axis.
Electrons cannot actually have negative kinetic energies. Whereas the double slit experiment initially indicated that a beam of light was a wave, more advanced experiments confirm the electron as a particle with wavelike properties.
The diffraction of a beam of light though a double slit is observed to diffract producing constructive and destructive interference. Modern technology allows the emission and detection of single photons. In an experiment conducted by Philippe Grangier, a single photon is passed through a double slit. The photon then is detected on the other side of the slits. Across a large sample size, a trend in the final position of the photons can be determined.
Under the wave model of light, an interference pattern will be observed as the photon splits over and over to produce a pattern. However, the results disagree with the wave model of light. Each photon emitted corresponds with a single detection on the other side of the slits Fig.
Over a series of measurements, photons produce the same interference pattern expected of a beam of photons. When one slit is closed, no interference pattern is observed and each photon travels in a linear path through the open slit. Fig 3, Proof for the particle-nature of photons.
One possible result is shown. This interference has a profound implication which is that photons do not necessarily interact with each other to produce an interference pattern. Instead, they interact and interfere with themselves. Furthermore, this shows that the electron does not pass through one slit or the other, but rather passes through both slits simultaneously. Richard Feynman's theory of quantum electrodynamics explains this phenomenon by asserting that a photon will travel not in a single path, but all possible paths in the universe.
The interference between these paths will give the probability of the photon taking any given path, as the majority of the paths cancel with each other. He has used this theory to explain the nature of wide ranges of the actions of photons, such as reflection and refraction, with absolute precision.
Calculate the energy of a single photon at this wavelength. A photomultiplier detects at least one particle in the 20 nm directly behind the slit. What fraction of the photon is detected here? The entire photon is detected. Protons are quantized particles.
Although they can pass through both slits, it is still a single particle and will be detected accordingly. The kinetic energy of the exiting electron is found to be less than that of the photon that removed it. Why isn't the energy the same? This equation relates the energies of photons and electrons from an ejection. The extra energy goes into breaking the association of an electron with a nucleus.
Keep in mind that for a metal this is not the ionization energy due to the delocalization of electrons involved in metallic bonding. One possible experiment utilizes the photoelectric effect. A light source is shone on a piece of metal, and the kinetic energy of ejected electrons is calculated. By shining the light at different distances from the metal plate, individual photons may be shown to undergo lossless transmission. The experiment will show that while the number of electrons ejected may decrease as a function of distance, their kinetic energy will remain the same.
Description Photons are often described as energy packets. As Described by Maxwell's Equations The most accurate descriptions we have about the nature of photons are given by Maxwell's equations. Creation of Photons Photons can be generated in many different ways. Blackbody Radiation As a substance is heated, the atoms within it vibrate at higher energies. Spontaneous Emission Photons may be spontaneously emitted when electons fall from an excited state to a lower energy state usually the ground state.
Flourescence Florescence is special case of spontaneous emission. Stimulated Emission An excited electron can be artificially caused to relax to a lower energy state by a photon matching the difference between these energy states.
Quantum mechanics does not allow different particles —photons and anti-photons, for example — to interfere with each other. By bending the rules to allow such particles with tiny charges to interfere, Altschul was able to estimate how coherence would be lost by photons and anti-photons travelling long distances.
He concluded that the charge on the photon and anti-photon is less than about 10 e. Close search menu Submit search Type to search. Topics Astronomy and space Atomic and molecular Biophysics and bioengineering Condensed matter Culture, history and society Environment and energy Instrumentation and measurement Materials Mathematics and computation Medical physics Optics and photonics Particle and nuclear Quantum.
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