Electrons Definition and 998 Threads

How much electrons do nuclei contain? Are there any numeric estimates around? I am quite aware that while estimating the numbers might be somewhat simple exercise for quantum mechanics, it is still complicated numeric computation which is not very closely related to observables, so somewhat...

With distance from the source the feild strength is reduced. Do the electrons travel slower the further from the source ? And thus faster closer to the source. Or is the feild strength reduced simply because there are less electrons but the speed of them is the same as inner feild. I'm asking...

Hello everyone. I am not a physics major or anything but have recently started finding it very fascinating and have been reading up on some of physics most popular experiments. I recently started reading about the double slit experiment to learn more about QM concepts like wave particle...

If you have many free electrons forming a cloud they wouldn't last too much as they would be repelled from each other due to electromagnetic forces. Gravity wouldn't help since it is much weaker than electromagnetic force, so electrons would still fly away However, can they be stabililized by...

If I'm not mistaken, in interstellar gas, there can be clouds of free electrons (not "attached" to any atomic nucleus) But can they stay like that indefinetely? Or will they inevitably end up in atoms? And how are they holding in interstellar gas inside of galaxies? Are they gravitationally...

Hi For a personal project, where can I find the free carrier density and the electron momentum relaxation time of various substances (i.e. Carbon etc .....). Is there a book or something ? Thanks. Adrian

Can someone provide me with a justification on this? As fair as I know current through an area is the rate of transfer of charge from one side of an area to the other. So how does current become 0 in a conductor (not connected to a circuit just a plain conductor) just cause "the number of...

I've been really confused on how electricity and circuits work 1. If eletrons "slow down" inside a resistor (or wire, I'm considering it's resistance to be ≠ 0) because of collisions with the lattice, then wouldn't the electrons pile up? The charges accumulating doesn't seem to be good. 2. Some...

Electric field is present . The net movement of electrons would flow in direction opposite to the electric field yes.But if we were to take a small cross section of the conductor and say 3 electrons are moving in slightly different directions would that not mean that it has 3 components to the...

From data of proton-proton collisions at the LHC using the ATLAS detector I have plotted a heatmap of the distribution of satellite clusters (brem and converted photons) around seed clusters (electron/photon candidates without satellites) at (eta, phi) = (0,0). The data I am using is of the...

I was thinking about this paper (https://arxiv.org/abs/1405.0298) where the authors argue that there wouldn't be dynamical quantum fluctuations in a De Sitter space as fluctuations would be static once all perturbative radiation escapes the horizon (in the case that the Universe has a finite...

Sorry to open a new thread. There are plenty of threads on PF dealing with the issue of "wave-particle duality". Although not unanimously, many agree that the concept of "wave-particle duality" is outdated. Electrons, photons and all of the underlying entities are neither waves nor particles...

Sorry for this question: how does a compass (or its electrons) know that it is in a magnetic field? Is it the information of the photons that cross it? (photons are what transmit electromagnetic forces)

Hi, what effect do gravitons have on electrons. I know with photons the electrons absorb the photons and leave the atom. Would gravitons have the same effect?

What is easily seen about how the internal structure of proton is explored is collisions of proton with electrons of high and varied energy. Electrons have an advantage that they are simple particles easy to handle: muons and tauons are short lived neutrinos are hard to aim and detect other...

My explantion of this electrostatic induction is that if the disc of electroscope is ground, electrons will flow from the ground and neutralize the disc, leaving the electroscope negatively charged after removal of the ground, but the book says it should be postively charged. As per book, the...

Ohm's law states that current is inversely proportional to resistance, but on the quantum level, why does that actually slow the current down for the whole circuit? In all of the basic explanations, it talks about how the more densely packed matter in the resistor creates more collisions and...

I am a Computer Science Engineering student at a local university in India and I was really moved by the CERN youtube channel and it got me curious about the particles like electrons and protons, I love symmetry in nature and was not a huge fan of proton being nearly 2000 times the mass of...

I have trouble researching whether valence-electrons take part in electrical conductivity. Some sources say that a lower amount of valence electrons lead to an higher electrical conductivity, whilst others say the opposite. And each have their different reasons, for example, lower valence...

when an electron is excited to the conduction band is it move further from the nucleus? Are free electrons in the conduction band further from valence electrons? I saw this picture that seems problematic to me. what do you think?

300 000km connect light bulb and battery. I would say 1sec is need from I turn on switch to light start lighting. This video say it is 1m/c...Is this video wrong? Do electron travels thorugh wire, if 300 000km wire is connected to bulb ,why electricitly travel through space only 1m??

Consider electrons in atom, and let's mostly ignore interactions between the electrons for now. What I mean by that is that the lowest energy level is the doubly degenerate 1s, then the doubly degenerate 2s, then the 6-fold degenerate 2p, etc. Textbooks like Griffiths use term symbols...

In the low temperature limit ##\mu \approx E_F## and the Fermi-Dirac distribution is ##n(E) \approx g(E)/(e^{\beta(E-E_F)}+1)##. An escaping electron contributes ##\Delta j_z = -ev_z = -ep_z/m## to the current density. How can I calculate the rate that electrons escape at? I can't see how to...

Can we all agree that electrons still move at absolute zero?

I want to characterize an electron beam using something like a CMOS-camera or maybe just a Faraday cup. The electron energy is between 1 and 10 keV and the expected total current around 10 microA for 1 keV electrons. Essentially I want to see whether the beam diameter is around 1 micrometer...

Can four (or more) electrons form a completely antisymmetric joint spin wave function？

Going back to high school chemistry, i remember being taught that the electrons in an atom can each be identified with four quantum numbers - one for energy, two for angular momentum and one for spin. These numbers are integers except for the spin quantum numbers, which are either 1/2 or -1/2...

I would say that for the elements with the lowest atomic numbers, because these elements have their nuclei the lightest and so they can move more and their movement influence electrons more than in some heavier elements, whose nuclei move less. Am I right or not?

For this problem, The solution is, However, is the reason why they don't include electrical potential energy because the time interval for which we are applying conservation of energy over is very small so the change in electric potential energy is negligible? Also, when they said, "electrons...

An interesting paper in NATURE "A superconductor free of quasiparticles for seconds" https://www.nature.com/articles/s41567-021-01433-7 showing that superconducting (paired) electrons don't hop into normal states for seconds. The measurement device detects single pair-breaking-events for a large...

I think there are so far as we can tell particles of mass that are made up of quarks and leptons (electrons and what not). So far as we know those the fundamental particles of matter. Question - how hard have we banged on quarks/leptons to see if we can blow those up into smaller units? I...

I'm wondering what happens when fast electrons (100 - 300 keV) interact with a beam (diameter 1 to 10 μm) of slower electrons (1 to 10 keV), which is at right angles to the trajectories of the fast electrons. The beam of slower electrons is relatively dense with 1 to 10 electrons per μm line...

In electron microscopy of thin solid specimens elastic scattering is treated as the main process responsible for formation of (phase contrast) images and diffraction patterns. However, if an electron changes direction it should lose energy by producing a breaking radiation photon. How can it be...

Trying to understand something fundamental about how magnetic fields are generated by moving electrons in a conductor. I have read many forums, studied Emag and am left with more questions. Looking for some practical insight not Bio-Savart derivations, etc. These still do not explain why the...

I was wondering if we could have an object made up of only electrons. Normally, that wouldn't be possible because electrons repel each other. However, this repulsion can be overcome using gravity. So my question is, how many electrons would you need to have their gravitational attraction...

Hello guys, I don't know if this is the right place to ask, so please be kind :/ I have a question regarding the location of an electron that belongs to an atom. A teacher told me that the probability of an electron to be found within its orbital is around 99%. When I asked about the remaining...

Im wondering if plasma is possible to be separated into a positive nucleus and negative electrons and contained within a magnetic bottle ? If possible, what is the most efficient method of achieving it ?

Hello, all! I've been trying to understand why the octet rule is followed, but I have not had much luck yet. Does anyone know why 8 valence electrons are ideal for the stability of atoms? I appreciate any help you can give!

I get step 1, in which due to electrostatic induction the top part of electroscope gets positively charged while the leaves of electroscope become negatively charged. Now if we Earth the positively charged end of electroscope as shown in step 2, then electrons must flow from Earth to...

Suppose in a Vacuum with no external influences we have two particle accelerators pointed at each other. They're maximally precise and one fires an electron while another fires a proton. Both the electron and proton have the same amount of momentum such that their x-axis velocity completely...

I am not sure if this is the way to ask questions here but having nobody to ask and little time, i hope i can get a fast reply here. So since the scaler the universe above us i.e. bigger than us is so huge and we aren't even sure about it further than sight (acc to my book), isn't it just like...

Hello! I have some electrons produced from a 3D gaussian source isotropically inside a uniform electric field. The electric field guides them towards a position sensitive detector and I end up with an image like the one below (with more electrons on the edge and fewer as you move towards the...

Common sense: walking on road, there is traction between shoes & earth. I'm wondering: same thing for electric current's electrons & copper wire?

This is a confusing question. I am not sure if electrons flow through the battery from positive terminal to negative terminal against the electric field within the battery; or the electrons deposit on positive plate resulting in a chemical reaction that releases electrons at the negative plate...

Hi, I would like to ask, why K-shell electrons coming from the internal conversion are much more frequent than L or M-shell electrons (see Fig). K-shell electrons are more tightly bound than L-shell, I would say that it is easier for gamma particle to kick off less tightly electron, no? Thank...

I am wondering what the public or mainstream scientists think of the statement that electrons being everywhere nowadays. If electrons are everywhere, can we assume space or void is just the totality of electrons?

We are given the resistivity of Gold. The length will be the outer radius minus the inner radius. We need to find the area. But I'm not sure how that would work given the spherical nature of the particle Would we need to use an integral to add up the increasing cross sectional area from the...

We need to find each variable. ##I## is already given to us as 8 amps. The charge of an electron is 1.6 x 10^-19 coulombs. The cross sectional area will just be ##\pi(1.2∗10^−3)^2## m^2. Now we need to find the free electron density. We are given the density of of copper and can use dimensional...

occup is proportional to [gi x exp(-Ei/kT)] where gi is the numver of states at energy Ei

[Mentor Note -- Two threads started by partners in a class have been merged into this one thread, since they are working on a shared solution to turn in]