Electron Definition and 999 Threads

The electron is a subatomic particle, symbol e− or β−, whose electric charge is negative one elementary charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron has a mass that is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum (spin) of a half-integer value, expressed in units of the reduced Planck constant, ħ. Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: they can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavelength for a given energy.
Electrons play an essential role in numerous physical phenomena, such as electricity, magnetism, chemistry and thermal conductivity, and they also participate in gravitational, electromagnetic and weak interactions. Since an electron has charge, it has a surrounding electric field, and if that electron is moving relative to an observer, said observer will observe it to generate a magnetic field. Electromagnetic fields produced from other sources will affect the motion of an electron according to the Lorentz force law. Electrons radiate or absorb energy in the form of photons when they are accelerated. Laboratory instruments are capable of trapping individual electrons as well as electron plasma by the use of electromagnetic fields. Special telescopes can detect electron plasma in outer space. Electrons are involved in many applications such as tribology or frictional charging, electrolysis, electrochemistry, battery technologies, electronics, welding, cathode ray tubes, photoelectricity, photovoltaic solar panels, electron microscopes, radiation therapy, lasers, gaseous ionization detectors and particle accelerators.
Interactions involving electrons with other subatomic particles are of interest in fields such as chemistry and nuclear physics. The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without, allows the composition of the two known as atoms. Ionization or differences in the proportions of negative electrons versus positive nuclei changes the binding energy of an atomic system. The exchange or sharing of the electrons between two or more atoms is the main cause of chemical bonding. In 1838, British natural philosopher Richard Laming first hypothesized the concept of an indivisible quantity of electric charge to explain the chemical properties of atoms. Irish physicist George Johnstone Stoney named this charge 'electron' in 1891, and J. J. Thomson and his team of British physicists identified it as a particle in 1897 during the cathode ray tube experiment. Electrons can also participate in nuclear reactions, such as nucleosynthesis in stars, where they are known as beta particles. Electrons can be created through beta decay of radioactive isotopes and in high-energy collisions, for instance when cosmic rays enter the atmosphere. The antiparticle of the electron is called the positron; it is identical to the electron except that it carries electrical charge of the opposite sign. When an electron collides with a positron, both particles can be annihilated, producing gamma ray photons.

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  1. F

    Electron microscope particle relativistic mass

    Homework Statement They were going to purchase an electron microscope, and wanted the electrons velocity to be as high as 25% of the speed of light after acceleration. There was a microscope at hand that had an accelerating voltage of 40 kV. a) How large is the electrons relativistic mass when...
  2. Gerry Rzeppa

    Electron Re-arrangement and Flow in Power Lines

    I've been doing some bedtime reading in Chabay & Sherwood's Matter & Interactions textbook (https://www.amazon.com/gp/product/0470503475/?tag=pfamazon01-20) and have come across some interesting tidbits. Here they are: I've always pictured electrons pushing each other through a wire, kind of...
  3. stackprogramer

    An electron in atom that rotate proton, has it radiation?

    Hi dears,i have a question about atom,in classic physics ,(Bohr theory) when a electron swing away a proton it have not radiates magnetic waves because if electron radiates magnetic wave it will drop on proton ,and atom will be Unstable! my question is ,in quantum mechanics that uses orbitals...
  4. O

    Electron potential/momentum problem

    Homework Statement To produce x-ray radiation, electrons are accelerated in vacuum and aimed so as to collide with a target. Assume that all of the electron kinetic energy is converted into the energy of the x-ray photon on collision and that the wavelength of the resulting radiation is 1.24...
  5. F

    Creating a positron and a electron with a photon

    Homework Statement Hi everybody. I have to demostrate that a photon, no matter it's energy, will never be able to create a positron and an electron on it's own. Homework Equations E=Sqrt(m^2+p^2) as long as c=1 Conservation of energy Ei=Ef; initial energy is equal to final energy...
  6. Z

    QM explanation of electron conduction in crystal

    Suppose that a static electric field E is applied on a conductive crystal. Then, how quantum mechanics describes the electron movements in the crystal? I have been trying to find an explanation, but have not found any. As I understand it, we could treat the E field as a time-dependent...
  7. TheExibo

    Why do noble gas electron configurations have large radii?

    In my lecture, we were told that a nitrogen with a negative 3 charge has the largest radius compared to most of the other atoms in the same period. How is that possible? It has more protons attracting the valence electrons closer to the center, but the prof said that because three electrons are...
  8. F

    Measuring spin of a free electron

    Hi everybody. I have been reading about the Stern Gerlach experiment lately and a doubt has came to my mind. Is there any way to know the spin of an electron without forcing it to interact with a magnetic field? Thanks for reading.
  9. N

    Electrons are not elementary particles?

    http://www.nature.com/news/not-quite-so-elementary-my-dear-electron-1.10471 Scientists have split an electron into 3 quasiparticles in the lab, why isn't this updated on the standard model?
  10. E

    Bohr model and relativistic electron mass

    From the semi-classical Bohr model of the hydrogen atom the velocity of the electron in a certain orbit can be determined. With these velocities the electron's relativistic masses can be determined. With E=mc2 the energy levels are in agreement with those from the Bohr model. I know Bohr's model...
  11. O

    Does Applying an Electrical Field to One Side of a Conductor Double the EMF?

    Assume a conductor in a rectangle shape for simplicity. Now, if I only choose one side of this rectangle, and apply external electrical field ∑ only to it, what EMF would I create on the conductor? I would simply say ∑, however then I had the following idea, and I started to doubt if I create...
  12. reemie

    How to calculate the mass of a hydrogen atom

    The answer according to my booklet is 1.6734×10-24 (g), but I don't understand how we got this answer. proton: 1.6725×10-24 neutron: 1.6748×10-24 electron: 0.0009×10-24 To get the mass, I added protons with neutrons, but I got 3.3473×10-24. What am I doing wrong?
  13. Yashtir Gopee

    B Electron Wave Behavior in Transistors - Yashtir Gopee

    Hello All, From my A'Level knowledge of Physics, an electron is both a particle and a wave but not both at the same time. I would like to know when does an electron behave as a wave (if it does) in a transistor? Thanks Yashtir Gopee
  14. A

    Average Electron Drift Distance with AC Current

    Homework Statement A metal wire with 1023 free electrons per cubic centimeter is carrying 60 Hz alternating current with a maximum current density of 100 amps/cm2. a) Write an expression for the average electron drift velocity as a function of time (vd as a function of time). b) What is the...
  15. K

    Work needed to move an Electron

    Homework Statement Calculate the amount of work (in electron-volts) it would take to move an electron from 15.1 m to 16.2 m away from a +3.50 μC point charge. Homework Equations W=qΔV (?) [/B]The Attempt at a Solution None yet. I'm not even sure where to start!
  16. Blackhawk4560

    Force on electron passing through Electric Field (calculate)

    Good afternoon, I hope this is in the right place... Anyway, diving right in- Say I have a classic CRT- How do I calculate the energy, in eV, that the electrons have upon reaching the anode? Also, is there a way to derive the speed of the electrons as well? See the attached image to...
  17. J

    What causes the potential energy in non-submerged electrons?

    The water analogy can be used as a rudimentary tool to describe an electronic circuit, but in the case of voltage on a wire, it is exactly analogous. When a voltage on a wire is induced, the power supply or battery is shoving excess charge (which moves to the surface of the conductor) into the...
  18. B3NR4Y

    Find the Speed of an Electron in the lab frame

    Homework Statement An electron moves to the right with a speed of 0.90c in the laboratory frame. A proton moves to the left with a speed of 0.77c relative to the electron. Using the Lorentz coordinate transformations, find the speed of the proton in the laboratory frame Homework Equations $$...
  19. Titan97

    Why is electron affinity positive?

    I was reading thermodynamics and about Born Haber cycle. There, I found that the values given for electron affinity are positive. When an electron is added to flourine, it attains noble gas configuration. So i t becomes more stable. So shouldn't the reaction be exothermic?
  20. Metals

    What happens if an atom's electron configuration remains unstable?

    What happens if an atom's electronic configuration remains unstable? So we know atoms react with each other to share or transfer electrons, causing them to bond. It's in their nature to do so; if they do not, they'll remain unstable (apart from some Noble gases which are already stable). What is...
  21. THE HARLEQUIN

    Understanding Electron Spin: The Mystery Behind a Fundamental Property

    okay , this question might look a little silly .. But i have been wondering about this for a while .. i know electrons move around the orbit because of the electrostatic force between electron and proton .. But what what makes an electron rotate about its axis ? i believe even without the spin...
  22. J

    Does a Buckyball spin like an electron or like a baseball?

    Does a Buckyball spin like an electron or like a baseball? We are often told that an electron does not really spin like a baseball. Only one (or two, if you count up and down) spin states, for example. How about a Buckyball? Does it spin more like an electron, or more like a baseball? Where...
  23. A

    Electron affinity, work function, band gap

    What exactly is the relation between these 3 quantities? As far as I can tell the work function is the energy needed to bring an electron from the fermi level out into vacuum, while affinity is from the bottom of the conduction band. Does this then mean that they can be used to calculate the...
  24. Garlic

    Muon and Electron Capture: Exploring the Differences

    I have read that an ordinary muon capture happen with this equation below: μ + p -> n + vμ It looks the same as the electron capture e + p -> n + ve I don't understand why there isn't any additional energy in the system, although a muon has a greater mass. Also, why isn't there an additional...
  25. Arpit Verma

    Energy for an electron in an orbital

    Is there any energy difference b/w two electrons of the same orbital having anti parallel spin?
  26. I

    Electron Charge: How Particles Get Their Charge

    How electron gets its charge ? For that matter any other particle charge?
  27. D

    What Lies Within the Electron?

    What is an electron made of? And don't reply that it is an elementary particle or a string.
  28. nilesh_pat

    Result of Bombarding Electron to any element

    What happen if we bombard Electron, Proton and neutron to any element in vaccume tube ? Will it change that eleement to another element obsorbing electron, proton and neutron or what will happen > With regards Nilesh
  29. F

    Rest energy of the electron - calculation discrepancy

    When I use E=mc2 to calc. the rest energy of an electron, I get .512Mev not .511Mev. I am using 9.109x10-31 kg for the rest mass of an electron and 2.9979x10^8 m/s for the speed of light in a vacuum. Can anyone tell me why there ís a discrepancy between my results and the accepted answer?
  30. Diploria

    In what sense do within-H-atom electrons "move" at ~1/137c?

    Hello, 1. I read here and here that in the hydrogen atom, electrons move at approximately ~1/137c. In the first link they speak of "zipping around the nucleus", presumably figuratively, because it is often stressed that QM has superseded the earlier model of electrons flying around. Instead we...
  31. Ryan Reed

    How to Graph an Electron Orbital?

    I've been really into electrons and their orbitals for a few months now, but I've never understood how they come up with all of these 3d models from these complicated equations. I would love it if someone could explain in detail the equations and the values of the variables and constants within...
  32. L

    Is an electron considered a singularity by some physicists?

    I read this book called How To Teach Relativity to Your Dog by Chad Orzel. In the book he discusses how an electron is known to have mass but is also considered a point like particle. He said that some interpretations consider the electron thus to have an infinitely dense mass which should...
  33. Ryan Reed

    Do Spin-Orbit Interactions change the Orbital of an Electron

    Does the orbital of an electron change when it experiences a spin-orbit interaction, and if so, how?
  34. E

    Mass of Electron: Relativity & Its Definite Mass

    If an electron moves at light speed, how do we know that it has a definite mass(9.1 x 10^-31kg)? According to relativity, shouldn't its mass be infinite?
  35. P

    How to remove electron gun from a TV?

    I'm trying to reuse an electron gun from an old black & white TV for an art project. I've posted into this forum rather than Electrical Engineering as I think that this is a strictly mechanical matter with no electricity involved. The TV's dead, and all I want is the physical bits of the...
  36. M

    Is there a difference between an electron anti-neutrino and a positron neutrino?

    Is an electron anti neutrino and a positron neutrino the same thing?
  37. Ryan Reed

    Does the Spin of an Atom's Electrons Affect its Orbital Configuration?

    In the stern-gerlach experiment, silver atoms with a +1/2 would be deflected up, and atoms with a -1/2 spin would be deflected down. With that in mind, would electrons' orbitals within an atom be affected by its spin?
  38. D

    Solid electron wavefunction localization vs delocalization

    In a solid, is electron's wavefunciton confined to a molecular orbital between atoms or is it delocalized and extends over the volume? According to valence bond theory, electrons are localized in bonds between atoms. But according to band theory (or Bloch wavefunctions), electrons are...
  39. P

    How to write electron hole Hamiltonian into quasi-boson?

    V Chernyak, Wei Min Zhang, S Mukamel, J Chem Phys Vol. 109, 9587 (can download here http://mukamel.ps.uci.edu/publications/pdfs/347.pdf ) Eq.(2.2), Eq. (B1) Eq.(B4)-(B6). When I substitue Eq.(B4)-(B6) into Eq.(2.2), I can not recover Eq.(B1). Who can give me a reference or hint on how to write...
  40. N

    Electron wave function in quantum cascade laser?

    How are these pictures taken of the electron wave function without the wave function collapsing? Does this mean that electron wave functions are real waves after all? Wikipedia Quantum cascade laser will give you the discription
  41. karakele

    Concerns about double beta decay plus/double electron capture

    Hello fellas! Ok, so we have the isotope Nickel-58 which can decay (still theoritically) to Iron-58 through double beta decay plus (bb+), my question is... imagine this decay is actually demonstrated (just figure it), so the transmutation into the iron isotope actually works... would the ejected...
  42. Shailesh Pincha

    What are the failed experiments to determine electron's position?

    What are some of the failed experiments to determine electron's position? One could be by electromagnetic radiation of suitable wavelength (here X rays) but that tears apart the atom. I want to know the different views tried to determine electron position.
  43. Mr Wolf

    Pauli Exclusion Principle: how does an electron know its state?

    This is one of those question you won't find the answer in any book. From Wikipedia: it is impossible for two electrons of a poly-electron atom to have the same values of the four quantum numbers (n, ℓ, mℓ and ms). But how can an electron know the state (the quantum numbers) of the other...
  44. N

    What if elementary particles do have size

    Is it possible that they have the structure something like we used to picture them as? For example, what if we captured an electron and zoom in with a microscope that see infinitly small distances. Is it possible that if we zoomed into the electron close enough that we would see an object...
  45. H

    Ionization and electron affinity

    I am confused about Ionization and electron affinity concept If energy is Required to add the electron to gaseous atom (Electron affinity - in case of noble gases) Then why further energy is required to Remove it? (Ionization energy) isnt this violation of Conservation of energy?
  46. S

    Exploring SEM Imaging: Cost & Advancements in Raster Scanning

    Looking at Ben Krasnow's youtube video on breaking down the parts and general cost for a scanning electron microscope, he lists a raster scan generator, is that able to produce the highest resolution images still? Or is there another more modern technology for this purpose? Otherwise, how has...
  47. T

    Why is electron gain enthelpy generally exothermic?

    I understand that we need to supply energy to counter the nuclear attraction when we remove electrons and that is the reason ionization energy is endothermic. However, why does an atom release energy when we add an electron to it? And also why do some elements( like the halogens) release more...
  48. Ryan Reed

    Does a Completed Electron Orbital Differ?

    In an atom of something like oxygen with a completed 2p orbital, do the paired electrons within the orbital behave differently than the same 2p orbital that is uncompleted? Bear with me and try to understand this question as I am a little fuzzy on the subject and I don't know how else to ask...
  49. Guidestone

    Strange questions about electrical circuits

    What's up people? I'm new in this wonderful forum. I have several questions about circuits, and they are not really common, I mean, I find them somehow complicated, but I would really come to enlightenment if you guys gave me some clues. 1.- So, let's suppose we got the simplest circuit, a...
  50. F

    Direction of Electron in Homogeneous Electric Field

    Homework Statement I'm right now trying to solve a question concerning the direction of an electron in an electric field. There is the picture I added given and you know that there is a homogeneous electric field. The blue line represents the movement of an electron (there is no movements up...
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