What is Electron: Definition and 999 Discussions

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. 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...
  2. 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...
  3. 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?
  4. I

    Electron Charge: How Particles Get Their Charge

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

    What Constitutes an Electron?

    What is an electron made of? And don't reply that it is an elementary particle or a string.
  6. 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
  7. 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?
  8. 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...
  9. 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...
  10. 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...
  11. 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?
  12. 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?
  13. 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...
  14. 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?
  15. 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?
  16. 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...
  17. 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...
  18. 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
  19. 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...
  20. 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.
  21. 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...
  22. 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...
  23. 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?
  24. 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...
  25. 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...
  26. 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...
  27. 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...
  28. 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...
  29. Ryan Reed

    Are Electron Orbitals Static or Dynamic?

    Do the orbitals of electrons change positions within their energy level relative to the nucleus or are they statically "attached" to the nucleus? To try and put this into perspective, would the orbitals of the electrons be like nailing a balloon(orbital) straight to the ball(nucleus) or nailing...
  30. nomadreid

    When r=0 in Coulomb's law; electron self-repulsion

    Given that (a) the electrostatic force is inversely proportional to r2 (b) that the electron is (when it is determined) a point (c) that the repulsion for an electron to itself is therefore r=0 (d) that r=0 would naively end up with infinite force What is the way out of this problem? Thanks
  31. Vannay

    Electron Transport in Bacterial Nanowires

    I was reading through a paper about the first case of experimentally proving that electron transfer can occur over the length of a bacterial nanowire. The paper mentioned that, previously, electron transfer was only measured across the thickness of the wire. "Thus far, there has been no...
  32. J

    Why Don't Electrons Stick to Protons: Exploring Positive/Negative Charge

    If positive and negative charges attract each other, why don't electrons just stick to the protons?
  33. Tam Le

    Electrostatic: Electron Transfer & Conductivity

    If you rub two electrically neutral pieces of insulation together, one piece becomes charged and the other piece becomes oppositely charged. Does this transfer of electron depend merely on the electron affinities of the two pieces, or does the conductivity of the two insulations play a part? I...
  34. P

    Electron microscope theory - job opportunites

    thankyou to anyone reading this. I am starting honours in physics and have been given the opportunity to do a project that leads to a phd in the condensed matter theory. The guy I will be working with seems to specifically do work around the theory involved in electron microscopes. hes a great...
  35. Dong Aleta

    Electron Configuration of Filled Valence Electron Orbitals

    Hi! I have understood how elements such as Be and Ca, with fully filled 2s orbitals, are not to be considered "noble" because they still have unfilled p orbitals. But I'm having trouble understanding how these elements participate in chemical reactions without having any unpaired electrons. My...
  36. K

    Does the concept of hole current hold up in metals?

    we generally talk about electron current in metals.but when an electron leaves, it leaves a hole in its place. does the hole current really exist in metals?please explain the stuff.
  37. A

    Electron beam hitting a metal plate

    So i have this simple situation where i have an electron beam with a certain kinetic energy, and i have a metal plate connected to the ground, and the electrons hit the plate, now i want to know the voltage of the current in the wire to the ground. Now i know both kinetic energy of the electrons...
  38. K

    Electron Refraction: Low Energy/Small Wavelength

    Hi All, Does a beam of "low energy/small wavelength" gets refracted when passing from one media to another. Thanks
  39. H

    Link between Green Glow and Electron

    hi, I just looking for Video on diffraction pattern of Electron, and noticed it produces green color pattern. Earlier in chapter, when cathode ray was discovered, it was mentioned that Green glow was Noticed. What is the reason for this green color?
  40. blue_leaf77

    Understanding X-ray Spectra: Characteristic vs. Background Radiation

    I'm looking at a program for Monte Carlo simulation of electron trajectory in a matter. When I look at the detected X-ray spectrum, there are two distinct curves, one called "characteristic", the shape of which is peaky. The other is called "background" where the shape is continuous. My...
  41. avito009

    Why does an electron not fall into the nucleus?

    Is it because the electron has less mass and is a point object that prevents it from falling into the nucleus due to attraction of protons?
  42. P

    Current density free electron gas

    Hello, I am studying transport in the free electron gas model and I don't understand how to compute the average of the electron density current. We are given the hamiltonian ## H=\int \psi^\dagger(r,t)(-\frac{\hbar^2\nabla^2}{2m}+e\vec{E}\cdot\vec{r})\psi(r,t)## where the ##psi## operator is...
  43. blue_leaf77

    Understanding the Energy of Electrons: Exploring 100 keV and Relativity

    This may be a naive question but this has been bothering me. I read that electrons having energy above 100 keV are considered as relativistic, on the other hand electron's rest mass is 511 keV. How can a free electron have energy less than its rest mass? What kind of energy implied in saying...
  44. M

    Electron between parallel plates

    If you place an electron between oppositely charged parallel plates, is it true the the force on it is the same regardless of how far it is from each plate? If so how?
  45. J-dizzal

    Vertical Deflection of Electron: 1.1×107 m/s & 3.2×10-16 N

    Homework Statement An electron with a speed of 1.1 × 107 m/s moves horizontally into a region where a constant vertical force of 3.2 × 10-16 N acts on it. The mass of the electron is 9.11 × 10-31 kg. Determine the vertical distance the electron is deflected during the time it has moved 34 mm...
  46. R

    How much work is required to stop an electron

    Homework Statement How much work is required to stop an electron (m=9.11×10−31kg) which is moving with a speed of 1.40×10^6 m/s ? 2. Homework Equations The Attempt at a Solution E.g a particle has KE=10J. The work that must be done on it to stop it is -10J. So work out the kinetic energy...
  47. M

    Single electron wave packet in Fock space?

    How might we construct a state most closely corresponding to the idea of a single electron wave packet as some superposition of Fock states?
  48. olgerm

    Schrödinger equation for 2 particles

    U(x,y,z,t)*ψ(x,y,z,t)-(ħ/(2*m))*(d2ψ(x,y,z,t)/dx2+d2ψ(x,y,z,t)/dy2+d2ψ(x,y,z,t)/dz2)=ħ*i*dψ(x,y,z,t)/dt qproton=-qe Schrödinger equation for electron in hydrogen atom (if we consider proton as point charge which is moving at a constant speed vproton→=(vp;x;vp;y;vp;z).) is...
  49. V

    Electron Rotation: Energy Source for Atom Motion

    Where from do the electrons in an atom get the energy to keep constantly moving around the nucleus of an atom
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