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. Nitheesh

    B Energy released in electron transition

    When an electron moves from higher energy level to lower energy level the energy doesn't released. But actually it should release. What happened to the in released energy?
  2. M

    Find Magnetic Force: Electron & Proton

    Homework Statement An electron that has a velocity with x component 2.1 × 106 m/s and y component 3.1 × 106 m/s moves through a uniform magnetic field with x component 0.035 T and y component -0.16 T. (a) Find the magnitude of the magnetic force on the electron. (b) Repeat your calculation for...
  3. K

    Copper Electron Pressure: 105atm & Its Effects

    The pressure of the electrons of Copper are about 105atm. Why, then, don’t the electrons in a piece of copper simply explode out of the metal?
  4. K

    Calculating molar heat capacity from electron contribution

    Homework Statement Silver has a Fermi energy of 5.48 eV. Calculate the electron contribution to the molar heat capacity at constant volume, Cv, of Silver at 300 K. Express your result as a multiple of R. Is the value of Cv due principally to the electrons? If not, to what is it due? ans...
  5. DjLeo

    The Charge of an Electron: Q = 1.6x10^-19C

    My question is, Why do we use q=1.6*10^-19 C rather than -1.6*10^-19 C, for the charge on an electron in most of the equations?
  6. A

    Finding the Electric Field of a Parallel Plate Capacitor

    Homework Statement An electron is launched at a 45∘ angle and a speed of Vo = 5.0×10^6 m/s from the positive plate of the parallel-plate capacitor towards the negative plate. The electron lands 4.0 cm away. Homework Equations F = ma = qE v = d/t s = vt -(1/2)at^2 x = 0.04 m The Attempt...
  7. Omega0

    What happens to an electron in a magnetic field?

    Let`s say you have a "magnetic field" (call it B) and let`s say it has a z direction, all over the space. Now let's kick an electron into the scene perpendicular to z. It will feel a force F=e v B to the axis z. Given a velocity v = v0 this won't change. We have an electron running in a circle...
  8. R

    B A question about Electron spin

    I was wondering just what physical properties of an electron influence it's probability of being detected in a certain spin state? For example, if I prepare an electron in the spin up state along say the way y-axis (vertical axis) and pass it through a detector that is at 0 degrees, then using...
  9. N

    Modeling an electric circuit by tracking individual charges

    Hello, Given a simple electric circuit like the one below (taken from Wikipedia) If we were to start from tracking all the forces acting on each individual free electron in the circuit, would it be possible to eventually find all the currents and voltages acting in the circuit? Probably a...
  10. Karan Punjabi

    Oxygen Charge & Electron Density in Simple Carboxylic Acids

    In any simple carboxylic acid there are two oxygen atoms then i have a confusion that which oxygen has more negative charge on it or which one has the most electron density on it?
  11. kiwaho

    A Anisotropic pinch force in high energy electron beam

    Here I am only considering 4 adjacent electrons in electron beam, especially the 2 electrons that are moving in tandem with velocity v. Moving charge will generate circular magnetic current. you can imagine magnetic flux as current, just like electric current. So, the question is same to find...
  12. otaKu

    B Binding energy of the electron in Hydrogen atom.

    This website here says that the expression for binding energy for an electron is: This http://ocw.mit.edu/high-school/chemistry/exam-prep/structure-of-matter/atomic-theory-and-atomic-structure/MITHFH_lecnotes05.pdfby MIT calculates it quantum mechanically to give: The book I was reading...
  13. Bill Myk

    Electron Motion in Magnetic Fields

    I hope I'm not violating any rules with this question i believe its the correct forum When free floating electron(s) enter a magnetic field @ a right angle, do they take a circular orbit around such field?
  14. Deepak K Kapur

    B Is an Electron Both a Wave and a Particle Simultaneously?

    An electron displays both wave and particle like properties. Does it exhibit these at the same time or at different times?
  15. kiwaho

    What material can act as electron sponge?

    We know Earth grounding is huge electron sink. But the Earth is not portable, what material can absorb lots of electron inside or on surface? Maybe the supercapacitors already use it as its cathode? and what material dislike electron and push electron away? thanks
  16. S

    B Carbon-14 to Nitrogen-14 Decay: Proton Gain & No Electron Loss

    How Carbon-14 effectively gains a proton but no electrons when decaying to Nitrogen-14...?
  17. S

    I Two Ferromagnets with Opposite Electron Spins

    What happens when two ferromagnets with opposite electron spins interact with each other? Assuming the magnets are placed in conditions under the Curie temperature of the material, would their spins not change because the magnetic susceptibility is not high enough? Thank you.
  18. Quadrat

    Electron passing through a magnetic and an electric field

    Homework Statement An electron with velocity ##\vec{v}_0=8.7*10^4(m/s)## (in the î direction) passing through an area with a uniform magnetic field ##\vec{B}=0.80 T## (in the negative k̂ direction). There's also a uniform electric field in this area. What is the magnitude and direction of...
  19. A

    Finding relativistic mass and energy of an electron

    Homework Statement A resting electron was sped up to 0.5 of the speed of light. Find: A. relativistic mass of the electron, B. total energy of the electron, C. kinetic energy of the electron. Homework Equations K = mv^2/2 E=mc^2 The Attempt at a Solution Let’s first find the kinetic energy...
  20. A

    Electron enters magnetic field at 5000V -- What's the radius?

    Hi! I'm getting ready for an exam and want to make sure if I solved some problems correctly. I would be grateful for your feedback :smile: 1. Homework Statement After going through potential difference of 5000 V an electron falls in uniform magnetic field. It’s induction is 0.1T and the...
  21. T

    Current of AC transmission lines and electricity in general

    Hi, I realized I didn't understand the physical model of something I know the theory of pretty well. I was considering the real power loss of an AC transmission line I2*R, then I realized that from source to load the electrons in an AC line don't actually move anywhere. (as far as I know) Yet if...
  22. P

    B Probability of finding an electron

    Let us assume that we have an electron belonging to the px orbital. In that case what would be the probability of finding it on the z axis? Would it be zero? My teacher says so, but I think that because we can't predict the boundary where there is 100% possibility of finding an electron, we...
  23. Y

    A Raman Spectroscopy vs. Inelastic Electron Tunneling

    I am a first year graduate student in physics and am becoming familiarized with Raman spectroscopy to study structure of materials based off of their vibrational states. In some personal study outside of this, I came across the idea of inelastic electron tunneling spectroscopy (IETS) and was...
  24. B

    Quantized electron orbits in Bohmian mechanics

    I entered in physicsforums archive search the wildcards "bohmian why electrons don't lose energy atom" but only got one hit that isn't related to it. In Bohmian mechanics, electron is localized and has trajectory.. why can't it lose energy as it rotates around the nucleus? What wildcard words...
  25. V

    B Deriving Electron Wave Function from Hole Wave Function

    Assume that i have a wave function of holes in a solid, can we derive the wave function of electrons? If can then how?
  26. G

    How to confirm unit of electron mobility as m^2/(V*S)?

    Hello. Electron mobility in plasma is μ = q/m⋅ν, where q, m and ν are charge and mass of electron and electron collisional frequency. (https://en.wikipedia.org/wiki/Electrical_mobility) And unit of the mobility is m2/V⋅S (https://en.wikipedia.org/wiki/Electron_mobility) According to the...
  27. Garlic

    I Electron wave energies different for +½ and -½ spin?

    Hello everyone, How come the electron wave energy states are different for spin -½ and +½ values? What causes this asymmetry?
  28. G

    Is collsional frequency actually frequency per an electron?

    Hello. The collisional frequency is generally expressed by ν = nt×average of (σv), where nt, σ and v are density of target (atoms or molecules), collisional cross section of target and kinetic velocity of incident particles. σ depends on kinetic energy of incident particles I thought...
  29. J

    I Electron motion in the plum pudding model

    Hi, I am trying to work out how the electron would oscillate about a mean position in the plum pudding model. Plum pudding model; -1 electron atom. -Positive charge of ##+e## distributed evenly about the volume of the atom of radius ##R##. -Electron (charge ##-e##) is free to move within the...
  30. Behrouz

    Exploring the Nature of Charge in Electrons and Protons

    Is it right to say that 'modern physics has no deep explanation of the nature of charge' in electrons and protons?
  31. Neha98

    Verify particle nature of electron using blackbody radiation

    It's mentioned in my book that blackbody radiation can verify the particle nature of electron could anyone explain this to me,please?
  32. F

    Perturbation matrix: free electron model on a square lattice

    Homework Statement Nearly free electron model in a 2D lattice. Consider a divalent 2D metal with a square lattice and one atom per primitive lattice cell. The periodic potential has two Fourier components V10 and V11, corresponding to G = (1,0) and (1,1). Both are negative and mod(V10) >...
  33. R

    Total energy of free electron gas

    Hello everyone! I encountered a problem about the specific heat of electronic gas and I do not understand a formula... so the problem says that experimentally it has been shown that the specific heat of the conduction electrons at constant volume in metals depends on...
  34. Zoey

    Is Electron Spin always Well Balanced?

    Just curious. Any answers would be appreciated. Thanks!
  35. N

    Electrons energy levels do not change with molecular bonding

    So if energy levels, or eV of electrons, do not change with molecular bonding, how are electrons influencing each other.? In glass, when individual atoms of silicon, sodium, and calcium come together, to form glass, the molecular bonding does not change the energy levels of the electrons for...
  36. A

    Position of electron motion 2D

    Homework Statement consider an electron traveling away from the origin along the x-axis in the xy plane with initial velocity vi= viî. As it passes through the region x = 0 to x = d, the electron experiences acceleration a = axî + ayj, where ax and ay are constants. For the case vi = 1.80 ✕...
  37. L

    Magnetic field energy of electron

    I've got a question regarding the magnetic field of an electron, and wheter or not it has some form of "self inductance" or resistance to be put in motion. The magnetic energy per volume is equal to u= 1/2*μ*H2. Say I've got an electron at rest, then the energy of the magnetic field is zero...
  38. L

    A Madam Wu's Experiment: Exploring Electron Behaviour in a Magnetic Field

    Why in Madam Wu experiment more electrons are not in direction of magnetic field? See Fig. Why there is not four electrons in the direction of magnetic field and two in oposite direction?
  39. T

    I How is a top gate used to change electron density?

    How is a top gate used to change electron density in 2D semi conductors? I get the principle, you are just shifting the chemical potential by some voltage so that there are more or less electrons in the specific bands. But how is it physically done? Thanks.
  40. J

    How to Calculate the Ground Electron Level Energy in a Quantum Well?

    Homework Statement For a GaAs with bandgap Eg =1.4eV Effective electron mass is 0.07*me d=10nm Calculate the energy of the ground (lowest) electron level in the conduction band with respect to the bottom of the conduction band.Homework EquationsEa =Ec + h^2a^2 / 8*me*d^2 The Attempt at a...
  41. Dr. Octavious

    I Electron number density in fusion plasma

    Hello everybody, Is there a way to calculate/predict the electron number density of a plasma? Thanks in advance
  42. B

    Electron shell further away from nucleus higher Energy lvl?

    Using electrical potential energy =1/4πεo Q1Q2/r , a particle further away from nucleus has lower magnitude of energy Using coulomb's law, a particle further away from nucleus experiences weaker attraction, hence less energy is needed to maintain orbit* around that e-shell compared to a...
  43. B

    Why does an electron shell further away from nucleus has higher energy?

    Using electrical potential energy =1/4πεo Q1Q2/r , a particle further away from nucleus has lower magnitude of energy Using coulomb's law, a particle further away from nucleus experiences weaker attraction, hence less energy is needed to maintain orbit* around that e-shell compared to a...
  44. NaiveTay

    B Two-Slit Experiment And Varying Electron Momentum

    There seems to be two divided approaches in how the uncertainty principle is explained, but they seem to be explaining two different things. The first, more intuitive explanation of the limits imposed by quantum mechanics goes something like: in order for a measurement to be made, we have to...
  45. A

    Electron Velocity Diffraction Grating Problem

    Homework Statement Suppose that visible light incident on a diffraction grating with slit distance (space) of $0.01*10^{-3}$ has the first max at the angle of $3.6^{o}$ from the central peak. Suppose electrons can be diffracted with this same grating, which velocity of the electron would create...
  46. N

    How Can Electrons Move to Higher Shell Levels Without Light Absorption?

    Can the Kerr effect have a effect on absorption, and transmission, of the electron.? Also is there any way to make electrons move to higher shell levels, without the electrons getting excited by light, and moving to higher Shell's. Or is light absorption the only way for electrons to move to...
  47. T

    Electron confined in a one dimensional box

    Homework Statement An electron confined in a one-dimensional box is observed, at different times, to have energies of 27 eV , 48 eV , and 75 eV . What is the length of the box? Hint: Assume that the quantum numbers of these energy levels are less than 10. Homework Equations E=h^2n^2/(8mL^2)...
  48. A

    Where does the magnetic field go for the electron?

    Homework Statement **Question** Is the magnetic field directed into the page or out of the page?Homework Equations Right Hand Rule The Attempt at a Solution My index finger is pointing downwards, and since the magnetic force is towards the right and this is an electron (negative) my thumb...
  49. AndresPB

    Medical What are the Technical Specifications for the KL27-0.8-70 X-Ray Machine?

    Good afternoon, I'm doing a research on x-rays machines. I chose the model KL27-0.8-70 (or any oral x-ray machine). I would be very grateful if someone could provide me some technical information as the radiation pattern, the aceleration efectuated on the electrons, and the electric field...
  50. I

    Beta decay, electron capture Q value

    Homework Statement Find the ##Q## value for electron capture of ##^{196}Au##. Homework Equations ##Q_\epsilon = [m(^AX)-m(^AX')]c^2-B_n## The Attempt at a Solution How do I know if I have an ##K##- or ##L##-shell for the electron? Assuming I have an ##K## shell taking ##B_n = \; ^{196m1}Au##...
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