Electron Definition and 999 Threads

Homework Statement What is the internal energy of an electron moving at 0.750c0 in the Earth reference frame? Homework EquationsThe Attempt at a Solution E = mc^2 E = (9.11 * 10^-31)(.750)(3*10^8) However, this appears incorrect. What have I done wrong or what am i missing?

Homework Statement What is the escape speed for an electron initially at rest on the surface of a sphere with a radius of 1.0 cm and a uniformly distributed charge of ##1.6\times 10^{-15}##? That is, what initial speed must the electron have in order to reach an infinite distance from the...

Homework Statement A charge Q = -820 nC is uniformly distributed on a ring of 2.4 m radius. A point charge q = +530 nC is fixed at the center of the ring. Points A and B are located on the axis of the ring, as shown in the figure. What is the minimum work that an external force must do to...

Is there a way in determining the distance between an electron and a positron as they anhilliate? If this figure has been determined already, what is it? Thank you very much for your help!

Electrons have both mass and electromagnetic charge, so why is it that an electron's rest energy is equal to its mass energy with E=mc^2? Shouldn't it have some energy left over to excite the electromagnetic field? The mass energy excites the Higgs field, so why is there no energy for the EM field?

Do electrons excite the EM field or do they just create virtual photons that do? If you could only see EMF excitations, would you see the electrons or virtual photons coming from the electrons?

While 2nd law of thermodynamics emphasizes past->future time direction, CPT theorem says that at least microscopic physics has some symmetry between past and future. For example the Feynman-Stueckelberg interpretation suggests to see anti-particles as traveling back in time. So thermodynamics is...

Hi, I have a couple of questions on photoelectrons. When a photoelectron of about 3-eV (varies) interacts within 0.2-um depletion region of silicon, what happens? I know, it will generate an electron-hole pair with an efficiency of 1 for 3.6-eV photoelectron. But what happens if the...

Imagine a semiconductor lattice - a regular lattice (e.g. of Si or Ga) with a small fractions of a different atoms (like Mn). The natural question is: how electrons flow through it? It can be measured experimentally: put a potential and use scanning tunneling microscope to map electron flow from...

Hello, I've been reading the Stern-Gerlach experiment, and where the concept of electron spin is introduced, am facing a problem, i.e., if you consider electron a charged rotating sphere, then the electromagnetic energy and size of the electron becomes huge! So how do you deal with this? Thanks...

I was watching a video about the double slit experiment because I found it interesting, However, watching this vid raised more questions than it did answer. I would like to know why did the outcomes of the experiment only change when we observed it... wasn't the electron interacting with...

Hello PF members, Source of the gravitational field in the Einstein field equations is energy–momentum tensor and the curvature of space-time is directly related to the energy and momentum of whatever matter and radiation are present. Suppose a electron at rest . 1- Can this electron be...

Hello, I would like to thank all of the contributors on this site. You have helped me in more ways than I can count. I am struggling with the following concept and was wondering if anyone could clarify this. As the electron gets further away from the nucleus, its energy increases. This makes...

There's a rule bout unlike charges attract and like charges repel one another. How is it that in chemical bonding like in covalent bonding electrons form a bond or there is attraction from one unto the other. Isn't that ironic?

1. Homework Statement An electron in the H atom falls from n=(?) to n=3. The wave length of the emitted photon is 1100 nm. From what level did the photon fall? Homework Equations Used the following to get the Energy. w = c / v E = h * v E = h * (c/w) w = lambda (couldn’t figure out how to...

Homework Statement Been looking but can't seem to find any comprehensive help on this. In the Hydrogen atom, what energy is associated with these electron energy transitions: a) N = infinity to N=2? b) N = infinity to N=3? c) N = 4 to N=2? d) N = 5 to N=6? I don't have any relevant formulas...

Homework Statement Calculate the de Broglie Wavelength of a 1 MeV electron. Express your answer in femptometers. Homework Equations ## λ = h/p ## ## p = (2mT + T^2/c^2)^{1/2} ## The Attempt at a Solution basically just plugged everything in. ## λ = \frac{h}{(2mT + T^2/c^2)^{1/2}} ## ## λ...

ZapperZ submitted a new PF Insights post See an Electron Lately? Continue reading the Original PF Insights Post.

Electron is usually imagined as a simple point charge, but in fact it is a very complex entity: https://dl.dropboxusercontent.com/u/12405967/electron.png - being electric charge itself means singular(-like?) configuration of electric field - E behaves like 1/r^2, - it is also magnetic dipole...

I understand that the result of the hydrogen emission spectrum experiment was that only certain wavelengths of light were emitted and that led to the conclusion that electrons emit light when they relax and that they absorb light when they get excited. How does that prove that the energy for...

1. The answer to this problem is easy when plugged into mathematica it's (pi^2)/3. I am trying to integrate it by hand however and can't figure out how to start it. I also can't find any other attempts of it online (our professor says we can just look it up if we can find it). [(x^2*E^x)/(E^x...

Homework Statement A piece of n-type germanium is 2.0mm wide and 0.25 mm thick. At a certain temperature, the number of conduction electrons per cubic metre is 6 x 1020 m-3. What is the average drift speed of the electrons when a current of 1.5 mA flows? (e=1.6 x 10-19 Homework Equations...

What is the relation between the orbital motion and velocity of electron? Do the electrons close to the nucleus have high velocities or those who are in higher orbits?

Can an atom exist without any electron? If yes, then how?

Homework Statement Electron with KE = 50eV is captured by Alpha particle, ie. HE++. Calculate the frequency of the emitted photon. Homework Equations KE = m/2 v^2; E=hf, En = Z^2*-13.6eV/n^2 The Attempt at a Solution Energy before = Energy after 50eV = 4*-13.6eV/1 + hf f = 1200nm

I am reading Frohlic's paper on electron-phonon interaction. Frohlic.http://rspa.royalsocietypublishing.org/content/royprsa/215/1122/291.full.pdf Here author has introduced the quantization for complex B field in this paper and claimed to have arrived at the diagonalized form of the...

Homework Statement An alpha particle: He++ captures an electron of a given kinetic energy. To conserve energy, it emits light, hf. How would one calculate the frequency? Homework Equations E=hf En = (Z^2 *-13.6eV)/(n^2) The Attempt at a Solution Calculate En. Then KE = Photon + En. Solve for...

When we observe an electron it is always a localized excitation in the electron field. But when it's not being observed, does the excitation begin to spread through space and become a delocalized excitation?

This is my attempt at understanding any real world physical effects from quantum spin. I will start with the short version first. A ... When we have a free floating electron in space is the physical orientation of the quantum spin axis locked into a fixed 3D orientation and from there can only...

1. Imagine a universe where electrons and protons have positive and negative electric charges, respectively. Could an atom consisting of one electron and one proton exist in this universe?2. None.3. My first thought was that such an universe already exists (ours) since an atom with a negatively...

Imagine a universe where electrons and protons have positive and negative electric charges, respectively. Could an atom consisting of one electron and one proton exist in this universe?

I guess my question has multiple parts. Any help in understanding the questions is appreciated. Assume a single electron in free space. The electron starts moving because of some force applied to it. The source of the force could be pretty much anything, let's say a uniform E-field in X...

Homework Statement In the circuit shown, two thick copper wires connect a 1.5 V battery to a Nichrome wire. Each copper wire has radius R = 0.009m and is L = 0.17m long. Copper has 8.4 \times 10^{28} mobile electrons/m^3 and an electron mobility of 4.4 \times 10^{-3}(m/s)/(V/m). The Nichrome...

Homework Statement A beam of electrons with kinetic energy 50 eV is fired at a 100 nm thick crystalline nickel foil. (a) Calculate the speed of the electrons in the beam.(b) Based on your answer to part (a), state, with justification, whether classical (Newtonian) mechanics correctly...

(1) electron = left chiral . anti electron = right chiral. positron = left chiral. anti positron = right chiral. So scalar couples L and R chiral fermion fields. (2)electron = left chiral . anti electron = right chiral. positron = right chiral. anti positron = left chiral. So scalar...

What cause the atomic orbitals electron configuration ? Thanks in advance

Homework Statement I am conducting some research and have come across a problem, it could very well be misunderstanding. I am trying to calculate electron density N.Homework Equations There was given a simple formula F = 9√N ... where F = critical frequency and N = electron density... But...

Hi, Can two free electrons in a vacuum become entangled as a result of a collision between the two? I have seen examples of electrons being entangled when bonded to atoms and in other circumstances, but not in this case. Can anybody shed some light on this topic? And, more...

When a galvanic reaction reclaims its (single) electron, magnetic energy (about 0.356 eV) within a superconductor will remain, w/o a means of replacing the galvanic electron. During the reaction, electrical current from the single electron would correspond to the number of times per second...

Homework Statement Show that the quantization of angular momentum implies that the kinetic energy of the electron is quantized as K=nhforb/2, where forb is the frequency of rotation. Assume circular orbit. Homework Equations Radial acceleration: arad = v2/r = (4π2r/T = 2*π*v/Tr = nħ KE =...

Homework Statement A electron cyclotron has a frequency of 2450 Hz and a magnetic field strength of 50T.? a) what's the speed of the electron? b) what was the voltage on the electron gun which projected the electron into the cyclotron? Homework Equations Givens: r=.4m B=50T f=2450Hz...

Homework Statement Which is the electron configuration of the Ni+ ion? Homework Equations Ni : [Ar]4s23d8 The Attempt at a Solution Ni+: [Ar]4s13d8 Apparently this solution is wrong and should be Ni+: [Ar]3d9 but I do not know why. As far as I know 4s has less energy than 3d so, why does one...

Hello. I have found an exercise that reads: "The wave function of a one-electron atom is: [1s orbital, atom: Li2+ What will be the most likely distance to locate the electron?" Solution of exercise is: My question is: Why the square of the probability density is dP/dV, and therefore the...

Homework Statement A sample of Si, in which 0<=x<=(25*10^-4), electron concentration is n(x)=5*10^16 cm^-3) * exp(-x^3/2*10^-8), temperature is 300k and electron mobility is 1300 cm^2/V*s. The electron current through the Si has both drift and diffusion components and total electron current...

1. Compute the Larmor radius for a typical electron in the K corona.2. , , m=9.11×10-31 kg, q=1.602×10-19 CThe Attempt at a Solution My problem is I don't know where to find the other two values that correspond specifically to the the K corona. Then it becomes a simple plug-and-chug problem...

I'm looking for a quick and well synthetized reference to the TEM technique. I'm writing a monography, we used TEM on a sample (just sended it to the lab, I dind't do the work). I don't have any reference, and I wanted to give a kind of introduction in the monography to TEM. I don't want a whole...

How the features of electron (or other elementary particle) like mass , electric charge ,magnetic moment and more represented in it ? Is each of the features should not be represented as a sub-particle in the electron ?

Which radiation emitted by an electron that moves in a circular motion ? And how radiation can be emitted by an elementary particle?

Hello friends Can anyone tell me the effective mass of electron in polyethylene and how it depends on the crystalline nature of polymer.

Homework Statement Electron is traveling in line with the equator, perpendicular to Earth's magnetic field of 6E-5 Tesla. What velocity is required for the electron to stay in a straight line path, such that it's weight is exactly matched by the magnetic force against it. Homework Equations...