What is Electrons: 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. gracy

    Do Free Electrons Decrease in a Conductor with Applied Voltage?

    when the external electrical potential difference is applied across the conductor ,electrons flow in the direction opposite to the current.Whether the number of free electrons in the conductor decrease? I think ,No.As electrons return ,because they move in closed loop.
  2. Eddie Sines

    What are the fine details of Type II superconductors?

    Independent research person who is working with Type II Superconductors. Would enjoy talking with fellow research people to discuss the fine details of Type II materials, specifically electrons and energy.
  3. S

    Auger electrons vs secondary electrons

    Hello everyone, the purpose of my question is to find out the way to separate AUGER from secondary electrons. I think? i know the way that each of them is produced but i cannot figure out how can we separate them since both come out of the surface of our material in a SEM let's say experiment...
  4. L

    Why do we draw unbonded electrons in pairs?

    A little background: I'm only a high school student with some knowledge on Lewis dot structures. And I don't know much about the s orbitals or p orbitals or whatnot. Why are there lone pairs? Shouldn't the electrons repel each other? Why do we draw them as pairs? For example: carbon dioxide is...
  5. K

    Electrons in Metal: Wave-Particle Duality

    Hi All, Lets assume, we have piece of cubic copper of side length 1 cm metal with neutral charge, so: 1) The free electrons in this piece of copper exist everywhere as waves? , each electron with its quantum state. 2) On applying an external electric field the wave-function collapse and they...
  6. H

    EM wave from electrons V protons

    this is theoretical (and possibly stupid) question; accelerating protons would create an EM wave equivalent to an EM wave generated by electrons at same frequency but the amplitude would be opposite, is that possible. has anyone made a communication circuit from accelerating protons? are...
  7. I

    If there are three electrons associated together then how

    If there are three electrons associated with each other in some kind of magnetic trap then will the middle electron be able to move freely towards either of the outer electrons or will the middle electron be held equidistant between the two outer electrons?
  8. I

    If electrons are fundamental particles then why do they -

    If electrons are fundamental particles and leptons then what happens when they emit or absorb photons or Z particles? What is known about the mechanism of these aborptions or emissions for any particles? Do the absorbed electrons gain mass as particles are described to do as they move nearer to...
  9. D

    I'm looking the paper first using the term Michel electrons

    Hi. First off, sorry if this is the wrong forum; this seems to be the most valid one, but if that's not the case please let me know. Anyway, I am writing a thesis, and in it I mention the Michel electron (electron created from muon decay) and note that it gets its name from Louis Michel. I was...
  10. thegreengineer

    Electricity. What kind of current should I use?

    Look, I found that there exist two kind of electric current: conventional flow and electron flow. I have read that in every situation I have to use the conventional flow, however I'm going to work with electric circuits using copper wires. In solids, only negatively charged particles (electrons)...
  11. A

    Filling bag with elementary particles

    Hello.This is probably totally stupid question, but anyway... Is it possible to create bag made of particles with very strong positive charge and electrons using attracting force between them? If theoretically at least in some parallel universe yes, then if we keep shooting electrons inside...
  12. B

    Electrons have to move -- why?

    Why? And how? Electrons has to move from one energy level to another?
  13. CAH

    WHY can't electrons absorb photons of any energy?

    hey! So oribital electrons can only absorb photons if they are the exact amount of energy between energy levels unless it is more than the ionisation energy. But why can't they? Couldn't they just emit the extra energy or 'keep' it? Thanks :smile:
  14. J

    What happens to the electrons in a black hole?

    As multiple stars would collapse into a black hole, are the electrons shot outwards? Or are they converted into mass with infinite density (what a black hole is right?) Thanks.
  15. CAH

    Electrons absorb exact energy photons so how is Ek possible

    Hello! I've read that electrons can only absorb photons of exactly the right amount of energy to move to a higher energy level, if its to little or too much then it doesn't absorb it at all, so my question: How can electrons be liberated from an atom with Kinetic energy when they can't absorb...
  16. 2

    Why removal of other electrons cause binding energy increase

    I'm talking about the chemical shift. In XPS test, oxidation leads to the increase of binding energy. This is determined by: 1. attraction between nuclear and the electron 2. shielding effect from outer-shell electrons My question is : What does shielding effect mean? Shield what? The positive...
  17. 3

    A heated cathode inducing thermionic emission of electrons.

    Hello all. I have been looking at this problem: I wrote three equations there, one for each part, which I think will help me solve each part; is my approach to the problem using those equations that you see there correct? I am just looking for some advice on where and how to start this problem...
  18. blue_leaf77

    "Wavepacket of electrons" or "wavepacket of electron"?

    For simplicity let's assume Gaussian shape. I just want to verify my understanding about wavepacket. As the thread title says, when we have a wavepacket, is it understood as the superposition of many plane waves corresponding to many free electrons, or as the wavefunction of only one electron...
  19. T

    Three electrons form an equilateral triangle

    1. Homework Statement Three electrons form an equilateral triangle 1.00nm on each side. A proton is at the center of the triangle. What is the potential energy of this group of charges? Known Variables: s = 1.00 × 10-9m p+ Charge = 1.60 × 10-19C e- Charge = -1.60 × 10-19C r = s/√(3) = 5.77 ×...
  20. A

    Solving My Confusion: States in Energy Band

    It's known that the number of states in a band is equal to the number of unit cells in crystal. Here is my problem (confusion with trivial concepts) Bloch function is a electronic state, or orbital. The number of orbitals in a band inside the first zone is equal to the number os units cells...
  21. D

    Why do parallel light beams not attract gravitationally?

    Say that two electrons travel in parallel at Ultra relativistic speeds, such that the observed energy-mass of said electrons (from a resting observer) is sufficient to generate a gravitational field great enough to overcome the repulsive coulomb force between the two electrons. This implies the...
  22. O

    How many electrons make up a charge of -90.0μC ?

    It says in question "Express your answer using three significant figures." Now; I know 1e = 1,6*10^-19C -90μC=-9*10^-5C N=q/e so (-9*10^-5C)/(1,6*10^-19C) =-5,625E+14 or -5,625*10^14 but that's a computer program so i don't know what it really wants from me i don't know my answer is true or...
  23. J

    Electrons & Gases: Changing Colour w/ Speed Increase

    What type of gas would change the colour of an electron beam as the speed of the electrons increases?
  24. J

    What would happen if a stream of electrons hits a conductor?

    I don't know much about particle physics, but out of curiosity I was wondering what would happen if a stream of electrons hit a conductor, say copper plating, an would it be detectible?
  25. S

    Permanent magnets: do electrons attract each other?

    When reading about the quantum explanation of permanent magnets, I only read about electron spins. Sure, but are they behind that aggressive attractive force existing between opposite poles? Common sense tells me the only things that should attract each other in a metal are electrons and...
  26. Astronaut

    Do electrons produce a constant magnetic field?

    I read somewhere that electrons produce constant magnetic field when moving with constant velocity. But I think it is not true.I thought a reason for it Imagine that an electron is stationary and I am moving with a constant velocity. In my respect electron is moving, so, it should produce...
  27. 7

    Materiel for fixed target particle collisions

    I am constructing a linear particle accelerator and have come into a problem, I need a materiel that when a electron hits it the electron breaks apart in smaller particles and the materiel breaks apart (on the subatomic level of course) as little as possible and make a little exes radiation as...
  28. S

    Why do the free electrons in the N-type want to diffuse?

    I'm trying to understand how a diode works and for this I've used(among other resources) the book written by Albert Malvino, Electronic Principles. Everywhere I read about this topic, it says that when the N-type and P-type semiconductors are joined together, the free electrons from the N-type...
  29. N

    Why do Electrons "want" 8 Electrons on the outter "shell"

    Why do Electrons "want" 8 Electrons on the outter "shell"? What is so special about 8?
  30. M

    Understanding Excess Electrons and Their Impact on Charged Objects

    When an object has excess electrons and is charged where are they? Are some of the molecules of the object given an extra electron? Also when two neutrally charged objects are rubbed together why do they both become charged? I would think that the electrons would prefer to keep both objects neutral.
  31. T

    Electrons and the Double Slit experiment questions

    First of all, I want to apologize ahead for three things: 1) Opening another tread about this experiment, with probably the same title than other 800 threads: I took a little time to read the other threads with similar titles and didn’t found this doubt in none of them, and also didn’t seem...
  32. H

    Energy of Electrons: Explained

    So when my book explains energy of electrons it says that the further an electron is from the nucleus the higher the energy, which is why orbitals that are further away have higher energy levels. Then later in the chapter it explains that the greater the distance between two electrons, the lower...
  33. L

    Electrons Disruptor: Exploring the Power of Gamma Rays

    What kind of beam can remove all the electrons of the target solid object and disrupt the intermolecular bonds disintegrating the object? Can gamma rays do it (enough energy to knock all electrons)?
  34. Q

    The electric repulsion of electrons and their attraction

    If electrons repel then why are particles attracted to each other so why do particles attract and what is the ratio of the gravitational attraction to the electric repulsion of both an atom and an electron? Thanks!
  35. X

    Can electrons "fly" between capacitor plates?

    How exactly do the electrons move from the capacitor to the rest of the circuit? Do they fly between the capacitors plates, or can they only travel where there is a wire connection? (I.e., if a small chunk of our circuit looks like this: A-------| |-------B can an electron start from A, go to...
  36. L

    Stern - Gerlach experiment with electrons

    Is it possible to perform am experiment like that of Stern-Gerlach but with electrons instead of silver atoms? Thank you. -- lightarrow
  37. N

    Electrons and Consequences of Conservation Laws

    Hi Guys, I was wondering; if electronic charge is conserved by Kirchoff's Current Law, then does this mean that the total number of electrons traversing any given circuit at any time is constant?
  38. Y

    Do Electrons Increase When Turning on a Light?

    Do the number of electrons flowing affect when we turn on the electric light
  39. O

    Is an Ionic Bond Not a True Chemical Bond?

    In a 2003 post about electrons and their behavior, which as a rule goes, tended not to get to a final solution, there was a quote by a poster: "There is no chemical bond between chlorine and sodium. That is to say it is only electrostatic attraction, an ionic bond as opposed to a covalent bond...
  40. C

    Spins on electrons versus photons

    Suppose you measure the spin of an electron with a sensor oriented in the +z direction and find that the spin is up (aligned with the sensor). Now if you immediately measure the spin of the electon with a sensor oriented in the -z direction, you are guaranteed that it will be down (oppositely...
  41. T

    What's the force moving electrons against E within copper-zinc

    I have a piece of copper in static condition. Since copper is a conductor, within the copper there is no electric field. Strange comes when I bring this copper in contact with a piece of zinc: in a tiny interval of time, certain amount of electrons would flow from copper to zinc. I suspect that...
  42. D

    Spin wavefunction for 2 electrons

    In 4-D Hilbert space for 2 electrons is |up1>|down2> equivalent to |down1>|up2> due to electrons being identical ?
  43. S

    Accelerating electrons in a cathode ray tube

    I have a question which has intrigued me for quite some time. If the electrons are accelerated using a potential difference in a cathode ray tube, the electrons should get accelerated till the time they reach the anode only. Once they cross over (ie. move to the other side of the anode), they...
  44. anorlunda

    Entanglement and Spin in Electron Interactions

    Consider two free electrons passing close to each other. They start in a product state, independent and not entangled. Then they might have an event which emits a photon and fall into a entangled triplet state or a single state, each of which have lower energy than the product state. Is the...
  45. psuedoben

    Quantum Leap: Electrons and Instant Movement

    Electrons can only exist at certain levels of orbit around the nucleus of an atom, meaning that when they leap, they skip the space in between the two orbitals all together. so if they do this instantly, there is no time between the electron being on one level of orbit to the other. I have seen...
  46. O

    What happens when a proton and an electron collide?

    I know this question sounds... find a word for it you like... But please bear with me. A proton. An electron. Not very high speeds...Vacuum.. A proton has an electric field, so does an electron... They arrive into each others' fields and start to accelerate towards each other... What...
  47. R

    Why the orbitals can contain maximum of 2 electrons?

    why orbitals like s, px, py, pz etc can hold maximum of 2 electrons? Why not some other number?
  48. M

    Velocity of electrons in a wire

    Electrons are moving in moves in all sorts of directions, causing the net electric charge to cancel out. But, when you apply a voltage, there's a small amount of electrons that will move towards the direction in the direction of the voltage. This is called the drift speed. Am I right? I read...
  49. Murdock

    Can electrons knock out neutrons?

    I know that sufficiently energetic protons and photons (1.7MeV) can knock a neutron out of a beryllium nucleus. Can an electron do the same?
  50. N

    Space between nucleus and electrons

    As the title suggests. What is the space between the nucleus and electrons of an atom? Thanks
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