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. 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?
  2. V

    Are the number of electrons on both sides of the radioactive decay balanced?

    Homework Statement Are the number of electrons on both sides of the radioactive decay balanced? Homework Equations For example, consider an alpha decay. ZPA → Z-2DA-4 + 2He4 For P, Number of Neutrons = A - Z Number of Protons = Z Number of Electrons = Z For D, Number of Neutrons = [A - 4] - [Z...
  3. S

    Can a beam of light guide or manipulate electrons in motion?

    Can electrons be "guided" or "carried" by a beam of light, something in the manner of how a ship can be guided by a current? So suppose we emit a uniform field of electrons. I don't know if field is the right word. I mean a bunch of electrons of more or less uniform distribution are being...
  4. P

    How many electrons does the atom have?

    Homework Statement A neutral atom is known to have a nucleus with a positive charge of 2.4 x10-12 C. How many electrons does the atom have? Homework Equations q=Ne The Attempt at a Solution None
  5. E

    Electrostatics and Electrons

    If we have two negatively charged bodies , say A and B, and body A has more electrons on its surface than Body B , would the electrons of body A transfer to body B?
  6. E

    Electrical current and electrons

    Electrons flow from negative to positive. But everything in nature moves from higher potential to lower potential, i.e the charges should move from positive to negative but they don't?
  7. P

    Mass changed if q is produced by adding to electrons mass

    Can someone walk me through calculating the final step in this problem. Problem statement: If the charge q is produced by adding electrons to the mass, by how much will the mass be changed? It was calculated that the charge q is 2.374 * 10^-7 C which is correct and I know that we need to...
  8. desta41

    Do just electrons emit photons?

    Do just electrons emit photons/radiation. Or do atoms and molecules emit photons as well? Just can't get a clear answer on this. And if atoms and/or molecules also emit photons, can you please explain what causes them to?
  9. M

    Why electrons never make contact with the nucleus?

    Hi everyone: This concept has bothered me for a while. The concept being that two oppositely charged particles (electron and proton) are attracted to each other, but the electrons go on a orbital trajectory around the nucleus instead of directly "sticking to" the nucleus. The closest I have...
  10. T

    Are colors a result of electrons or the atoms themselves?

    Hi Everyone. I am confused about the science of colors. I will use an example in my question. I know that the color blue is caused by atoms reflecting blue wavelengths of light and absorbing other wavelengths of light. What I don't understand, however, is which part of the atom actually absorbs...
  11. R

    Fermi energy of multiple electrons, infinite potential well

    Homework Statement [/B] Five free electrons exist in a three-dimensional infinite potential well with all three widths equal to a 12 angstroms. Determine the Fermi energy level at T 0 K. Homework Equations E = [(h_bar*pi)2/(2*m*a2)]*(nx2 + ny2 + nz2) The Attempt at a Solution Tried using EF...
  12. 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...
  13. M

    Help:Why do electrons go from negative to positive?

    Hi, I'm confused and need some help. What I thought happens in a battery is that the anode (the positive electrode) attracts the anions, it then goes through oxidation by taking the electrons and those electrons move through the closed circuit to the cathode and reduction is done. If that is...
  14. Gerry Rzeppa

    How Does Motional EMF Affect Electron Distribution in a Conductor?

    Here is a typical description of motional EMF: "The figure below shows a conducting rod of length L being moved with a velocity v in a uniform magnetic field B: The magnetic force acting on a free electron in the rod will be directed upwards. As a result, electrons will start to accumulate...
  15. R

    Circuit Questions -- Electrons flowing in wires and a resistor

    Homework Statement Homework EquationsThe Attempt at a Solution I have selected what I thought were the right choices in the original question. Resistors reduce current so electron flow should have been greater on the right. Also, the electrons flow opposite to current so potential is higher...
  16. N

    Fundamental point like particles?

    Is it possible that fundamental point like particles (ie electrons) are actually particles with shape size and structure that are too small for any of our current technology to detect?
  17. U

    Are there any real-life examples of tangent waves in the universe?

    I'm in high school, just finished Grade 11 and I have learned about sine, cosine, and tangent waves in my math & physics classes. The question is more of where are tangent waves found in nature/this universe? I have thought that maybe electrons experience some sort of tangent wavelike behavior...
  18. person_random_normal

    Drift Speed of Electrons in Conductor with Applied Field

    for an electron, randomly moving inside a conductor , having applied an external electric field we have those electrons moving with a net speed called drift speed , against the direction of field. so initially as electrons are moving randomly we consider their initial velocity o and after time t...
  19. S

    Exploring the Science Behind Flame Electrons and Ions

    why would a flame contain electrons and ions??
  20. Tonia

    What is the max. # of electrons located in the ground state?

    < Mentor Note -- thread moved to HH from the technical chemistry forum, so no HH Template is shown > I need someone to check my answers and help me with the questions I couldn't answer. What is the max. # of electrons located in the groud state of a) an orbital 2 b) d sublevel 10 c) Be atom...
  21. ORF

    Particle beams: energy of released electrons

    Hello When a beam* pass through a thin layer of material (some microns), at the exit some electrons are released; so a electron cloud is formed around the exit point of the beam. My question is: what is the energy distribution of these released electrons? (Maxwell, random,... ) I think they...
  22. akashpandey

    Why flow of electrons through a conductor produce magnetic field

    i want to know why flow of electron produces magnetic field sombody says this is because of spin of electron or because of flow of charge or relativity of flowing electron. anybody please clear my confusion?
  23. Luke Cohen

    What is the charge (Coulombs) of a nanogram of electrons?

    Homework Statement What is the charge of a nanogram of electrons? This was a test question for me. I didn't know the exact definition of a coulomb, so I guessed about 1. something C. The options were 1.something C, 0.03C, or like 3.64C. Someone care to explain/help? thanks Homework...
  24. Priyank

    Exploring the Drift Speed of Electrons in Conductors

    Homework Statement :[/B] When a steady current flows through a conductor, the electrons in it move with a certain average 'drift speed'. The drift speed of electrons for a typical copper wire is about 1 mm s-1 . How is it then that an electric bulb lights up as soon as we turn the switch on...
  25. T

    Chemistry Moles of electrons that weigh 1 kg

    Homework Statement How many moles of electrons weigh 1 kg? Homework EquationsThe Attempt at a Solution We know the mass of an electron= 9.1*10-31kg. So no of electrons in one Kg will be 1/9.1*10-31. Then we just divide that by 6* 1023 to get the number of moles. But my teacher told...
  26. avito009

    Same distance of electrons from the nucleus for same element

    Why distance of electrons from the nucleus is the same for same element?
  27. Alex299792458

    Why do electrons have band widths or energy bands?

    So I know glass is transparent because the electrons have energy bands(or the energy to get it up to the next energy state) that are beyond the energy of visible light. But what I what to know is why do the electrons have energy bands because every single electron is the same and there all...
  28. F

    What is the resonance frequency for oscillating electrons in a metallic net?

    hello I suppose electrons oscillate, so do electrons have resonance frequency? ie. a frequency where the amplitude is maximum? and where can I find it? thanks
  29. desta41

    Vibrational frequency of electrons in atoms

    Below is a paragraph taken from the web site, physicsclassroom.com: 'It is often useful to think of these electrons as being attached to the atoms by springs. The electrons and their attached springs have a tendency to vibrate at specific frequencies. Similar to a tuning fork or even a musical...
  30. TruBlu4AU

    Electrons at rest have magnetic fields

    It could be that I'm misinformed, but I heard electrons at rest have magnetic fields. I thought that magnetic fields required a charge to be traveling at velocity before a magnetic field would arise. If this is the case could someone help me out? If an electron has a magnetic field at rest what...
  31. M

    Can electrons lose their charge?

    Hello! I am trying to understand electricty. I know that electricty is a flow of electrons which move around a circuit. And that electrons have negative charge. But as they move around the circuit do they lose their charge? Does the amount of charge cahnge? Any help would help Mark [Mentor's...
  32. N

    Excitation of electrons by electromagnetic source

    If you hit a bound electron with a photon corresponding to that electron's ionization energy, you ionize the electron. What if you hit the electron with a photon with less energy? Will the photon still add its energy to the electron? Will the electron re-emit the photon with less energy? Do you...
  33. K.Callaghan

    Energy of an electron at rest?

    An electron rest mass in kilograms is calculated from the definition of the Rydberg constant R∞: where α is the fine structure constant and h is simply Plancks constant. Now, assuming the electron has an associated rest energy, Any idea on how this is calculated? I'm assuming using...
  34. N

    Electric field needed to excite electrons to conduction band

    What's the electric field strength needed to get one of lithium's core electrons into the conduction band? How do you figure this out?
  35. V

    No. of Electrons on Hard Disks: New vs Used

    Is the no. of electrons on a brand new unused and untested harddisk is different from no. of electrons on a used hard disk completely filled with data. i mean will there be even a change of one electron? Please consider the following points before answering: 1- Does all the electrons from a...
  36. B

    How do the electrons enter the bubble chamber?

    How's the electrons of the accelerated electron beam enter the bubble chamber that contains the liquid hydrogen? Wouldn't the high intensity of the electron beam cause a massive explosion and destroy the bubble chamber that has an outer wall of at least quarter inch of steel! I think hydrogen...
  37. A

    Gravitational force between two 1g masses of electrons

    Homework Statement Imagine you could place 1g of electrons 1.0 m away from another 1g of electrons. calculate the electrical force and gravitational force between them. Homework Equations fe= kQ1Q2/r^2 fg=Gm1m2/r^2 The Attempt at a Solution So the number of electron is N= 0.001 /...
  38. Lance Fernandes

    Frustrated about electrons and touching.

    I know there's been loads of discussion about this everywhere, but- why don't we touch things at the microscopic(or quantum, whatever) level? I know that it has to do with the Pauli Exclusion Principle, and the Van der Walls force- but- could i just get a plain clear( i know what I'm asking for...
  39. slitted

    Observer Big Bang? How come electrons have a wave nowadays?

    Hi. From what I've read about the "observer effect" in the two slit experiment, the electron's wave function collapses due to photons altering its momentum. Now, in the beginning of the universe photons couldn't escape the original Big Bang fog until it cleared out, so these should have...
  40. aditya ver.2.0

    How do electrons get a charge?

    My question is why only protons and electrons have a charge?Why not neutron?
  41. T

    Wave packet description of electrons in solid state physics

    In solid state physics, I learned that the velocity of a bloch electron is ##\frac{\partial E(k)}{\partial k}##, where ##E(k)## is the energy dispersion. This formula is derived on the basis of the assumption that electrons is a wave packet of bloch state in solids. However, I have a question...
  42. S

    Interaction mechanisms of photons and electrons with matter

    Hello everyone, I would like to ask a couple of questions related with the interaction mechanisms of photons and electrons with matter. Through searching about this subject, I have concluded that they both have different penetration depth and different interaction mechanisms. But apart from...
  43. A

    Resistance of Electrons in Wire: Factors & Theories

    I'm not sure if this question has already been answered yet. I was curious what factors effect the resistance of electrons moving through a wire? From the formula R = p*(L/A) i see mathematically why but I'm curious to the theoretical. Does an increase in cross sectional area decrease the...
  44. M

    Understanding Electron Liberation in Relation to Light Frequencies

    In my physics class we are learning about certain frequencies of light hitting and "liberating" electrons, but we didn't go into any detail about what "liberating" the electron means. Can somebody explain?
  45. O

    Finding speed of two electrons initially at rest

    Homework Statement Two electrons start at rest with a separation of 5.0 x 10^-12 m. Once released, the electrons accelerate away from each other. Calculate the speed of each electron when they are a very large distance apart (Ee = 0). Homework Equations EE = kQq/r Ek = (1/2)mv2 The Attempt at...
  46. K

    How many electrons make up a charge of -15.0 uC?

    So I've already got some help on this one, now I have a different question pertaining to this equation. I know N=q/e e=-1.6x10^-19 q=-15x10-6 so I tried: N=(-15x10-6)/-1.6x10^-19 N=-156/-1.6x10^-19 N=9.74 ~that was wrong So I thought maybe this: N=(-15x10-6)/-1.6x10^-19 N=--60/-1.6x10^-19...
  47. H

    Does light cause electrons to constantly change state?

    Im trying to wrap my head around this. If a photon of the right energy hits an atom's electron (hydrogen e.g) it jumps to the next orbital shell, then goes back down to conserve energy releasing a photon in the process. is this how we see the atoms in everyday matter? by the switching of the...
  48. A

    Calculate the wavelength of electrons traveling at 1.15x10^5

    Homework Statement Calculate the wavelength of electrons traveling at 1.15x10^5 m/s Homework Equations λ = h/m*v Given values: h=6.626x10^-34 J*s m=9.11x10^-31kg v=1.15x10^5 m/s The Attempt at a Solution I converted J*s to SI units (kg⋅m2⋅s−2) and then substituted out all known values, to...
  49. J

    Is the Net Charge of a Hydrogen Atom the Same in Excited State vs Ground State?

    if in a hydrogen atom the electron is in a excited state, is the net charge the same vs ground state? what is the difference between charge and energy here? thx
  50. M

    How do electrons know that there are other resistors?

    If there is only one resistor, the voltage drop is equal to the potential of the positive terminal. The voltage drop across more than one resistor is directly proportional to the value of each resistor. But the total drop in potential difference must be equal to the potential of the positive...
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