Electrons Definition and 998 Threads

An magnetic field can make a current flow of electrons. But can the magnetic field make the protons move or is it "just" the electrons that flow?

In a semiconductor, is the chemical potential of electrons limited to take values only between the valence band maximum and conduction band minimum? Are there circumstances where it can cross these bounds?

Hi All, I am preparing for PhD quals and have been looking at problems from other universities. I came across this one and am stumped on how to tackle it. " Assume that the neutron density in a neutron star is 30.1/fm (that is 0.1 neutron per cubic Fermi). Assuming T=0 and ignoring any...

i everybody i've studied in my 9th standard that x rays are produced when cathode rays(electrons) hit solid targets such as molybdenum,titanium,etc.. now we'll observe the physics going out there so what's happening there? an electron is coming with some speed say v and hitting the valence...

Hi, I wonder if there is an elegant way of how to picture (or describe at all) the transition of free electrons (non-quantized, point-like charges) into let's say the bound ground state of the hydrogen atom (in which it becomes quantized and cloud-like). How does the transition occur ? When...

Homework Statement A charge containg 3.7x10^14 electrons flows throug a wire in 150 uS(micro seconds. What is the current? Could some assist me. Is there a shorter way to arrive at the answer? Homework Equations The Attempt at a Solution

Do electrons lose heat? If they do, how do they do it? Bremstrahlung for free electrons and going down to a lower energy level for bound electrons? If you had say a metal and cooled it down, would the electrons move slower or just jump to lower energy levels and lose photons?

Homework Statement When you rub a gold sphere with rabbit's fur, the gold takes on a negative charge (and the rabbit fur positive). Suppose the gold sphere has a mass of 190.0 g and it obtains a net charge of 0.540 μC. Calculate the ratio of the number of electrons added to the gold sphere to...

Hello. I'm now working in the spectroscopy and I'm wondering in one instantaneous moment of ionization. Let's have an atom with multiple bound electrons. The external energy (like in form of photon) is introduced on the atom such that outer bound electron is ionized and the question...

Homework Statement Flow of 500 electrons per second with kinetic energy 3 eV hits a perpendicular 5 eV potential hole 0.3 nm wide. How many electrons pass per second pass the obstacle? Homework Equations The Attempt at a Solution Hmm, I checked my notes where it is written that...

Ok, so I have been searching around the internet for an answer to this and have not found anything besides the fact that electrons move in a quantum way, that is jumping from one place to another without passing through the space between those two places, which I am aware of. So the two main...

Cathode rays are the flow of election, since electrons are -vely charged, is it normal for the rays to travel almost in a bundle without getting dispersed due to it's repulsion? If you say it's because of its velocity, then if you imagine each electrons, they are at almost rest to each other...

X-ray crystallography is now 100 years old so this question is probably pretty simple. Is the diffraction coming from the nucleons or the electrons in the sample? Ie. The electrons occupy a more diverse location within the sample (depending on what level/shell they occupy, in fact some may be...

i have read around the forum that the speed of electrons in a conductor is somewhat 1mm/s if that is true , then how do galvanic cells operate ? by that rate , about 1000 electrons would come out of the conductor / sec , not only this , but it would seem like the velocity of electrons is...

Hello, I have a rather conceptual question I couldn't really find an answer to yet. The electric field lines of an isolated resting electron would simply point from everywhere in space towards the position the electron is located in, with a length inversely proportional to the squared distance...

Homework Statement Why, IF electrons really orbited atoms, would they lose energy? Homework Equations The Attempt at a Solution I realize they're meant to emit light. But why? I understand vaguely that the E field might be changing with time, since you have a changing magnetic flux... but...

double-slit experiment and "watching the electrons" I'm trying to build a picture of what is happening in the double-hole experiment when you are "watching the electrons" (http://feynmanlectures.caltech.edu/III_01.html#Ch1-S6). It's mostly clear to me but I do have some questions: if you use a...

Homework Statement A hydrogen atom in its ground state actually has two possible, closely spaced energy levels because the electron is in the magnetic field B of the proton (the nucleus). Accordingly, an energy is associated with the orientation of the electron's magnetic moment (μ)...

Hi , now I was thinking what happens with the electrons that are in the middle of the polywell trapped by the magnetic field coming from the coils? Assuming there is plasma and some fusion takes place at some rate " x" , what actually happens with the electrons in the middle , do they say there...

Homework Statement Hey guys, So the title pretty much says it. I have to find the total charge density produced by all the electrons in a closed subshell where n = 3 and l = 2. The charge density produced by a single electron is (-e)|R_{32}(r)Y_{2,m}(\theta , \phi)|^{2}Homework Equations So he...

Both photons and electrons give the same kind of interference pattern in the double-slit experiment, but while in the case of electrons this carachteristic interference pattern is due to the probabilistic complex wavefunction of the Schrodinger equation within NRQM, for photons no such...

Hello,Im reading a article about water spliting device in which all necessary charge carriers for water spliting arise from surface plasmons. This is the article: http://www.nature.com/nnano/journal/v8/n4/full/nnano.2013.18.html#f1 So i do not understand how charge carriers arise form...

How do you count the number of valence electrons for an element? I mean with the shell model it is pretty obvious but the electrons are actually in orbitals.

Suppose I'm holding a magnet and then lift a paperclip(or another magnet) with the magnet. Now the energy density of a magnetic field or the energy that went into making the magnetic field is W = \frac{1} {2 \mu_o} \int B^2 d \tau but since work was done in lifting the magnets, what happenes to...

Homework Statement The threshold frequency of a metal is 3.184 x 10^14 Hz. If a photon of wavelength 368 nm strikes the surface of the metal, what is the wavelength of the ejected electron? Homework Equations f (frequency) = c/(wavelength) Eincident = Ethreshold + KE E=fv(wavelength)...

Were electrons to be slightly different sizes, or have different strengths, or slightly different spin moments, then what effect might this have on the fundamentals of quantum mechanics? So fart, we "assume" an electron has certain characteristics, but are they all the same??

Homework Statement What is the minimum amount of kinetic energy of electron that hits another electron, so ectra electron-positron pair is produced. Homework Equations ##p^{\mu }=(E/c,\vec{p})## The Attempt at a Solution Before the collision: ##p^{\mu...

I had to clear this up since there were many threads with the wrong analysis of this problem. Lone pair electrons DO have and affect on dipole moments. Lone pair electrons do have an effect on the net dipole moment of a molecule. A dipole moment is the product of the magnitude of the partial...

What would happen if you place a substance containing bonded and paired electrons, such as a biological organ, and place that substance in a homogenous magnetic field? Would the electrons align with the field? I'm a little confused by what an electron pair is. I pretty much know the pauli...

Are paired electrons at a spatial distance from one another or are they "mixed" in some way. Why do their magnetic poles cancel?

As far as I understand: In the Drude model we take the electron to be moving in a random direction after each collision (*), such that the mean velocity is simply the average of -eEt/m, which is just -eEτ/m, where τ is the relaxation time. But I am very confused about this basic assumption...

Why can have transition metals unpaired electrons in their compounds? In correlates to their multiple oxidation states, but I still don't know the explanation of it, that would make me satisfied - I suppose it's mathematical, as molecular orbitals are creating. Or is there any explanation?

Consider two parallel streams of electrons in vacuum. Each stream moves with constant velocity and carries a current. According to classical electrodynamics parallel and same direction currents attract each other. The problem is that I can't see how relativistic length contraction can cause...

When you place a diamagnetic material in a homogeneous magnetic field, do the electrons of the material align with the field?

Homework Statement A small plastic sphere is suspended between two parallel plates like so: http://gyazo.com/0b5425a78b645d85da0b3475d6d71734 How many excess or deficit electrons does the sphere have? Homework Equations ##m=2.60x10^{-15}kg## ##V=265.4V ##...

I was wondering why the valence electrons aren't free to move in insulators? Thanks for any help in advance.

Homework Statement 1) Apparently it's a true statement that the quantum numbers 2, 0, 0, 1/2 can apply to any of Cl's electrons. But chlorine's electron configuration is [Ne]3s^2 3p^5. What happened to the n = 3 electrons? 2) How many valence electrons can a ground state oxygen atom have...

Homework Statement Note this is a PRACTICE midterm problem. Not due for homework or for a grade. My exam is on Tuesday "an electron moves from point A to point B in a uniform electric field as show below. Rank the electrons in diagrams 1 through 2 by the changes in potential from greatest...

Does the electron emit electromagnetic waves?

Let's say we have 200 electrons. The first batch of 100 of those electrons are prepared in a way that 50% are UP in the x-axis while 50% are DOWN in the x direction. The order is unknown. The second batch of 100 electrons are prepared in the same manner but in the y axis. Bob picks one...

My answer key claims it's answer E. I don't think it's right; I think it's cobalt with three unpaired electrons. Not four. A 3d7 configuration, through the Aufbau principle, would fill two of the five d electron pairs completely and leave three half filled. This works mean it's also para...

Hi, I read that heat is the oscillation of atoms. Is it only the nuclei that vibrate or also the electrons? If so, how can they rotate and vibrate? How do electrons react to heat, anyway? If a beam of electrons is rotating in a magnetic field and we heat up the container/the room, how...

According to QM, given two entangled electrons A and B, if you measure the y-axis spin on A to be up, then you know electron B's y-axis spin is down. Also according to QM, if i understood it properly, you cannot then go on to measure the x-axis spin on B, because then you would know both y...

σx|x>=+|x> σx|-x>=-|-x> These equations also follows for σy and σz corresponds states |y> and |z>. if we measure along axis X then X state vector let it go which means up spin and opposite not go through which means down spin. and also same for y and z axis. But, σx|u>=|d> σx|d>=|u>...

Copper has one valence electron, but it can lose more than one when forming cupric compounds. I had thought it could only lose the valence electron. How can this happen? If this is true, how does an electron from the d orbital jump to a higher orbital if only valence electrons can make the jump?

We know that can't measure both position and momentum simultaneously whether both are orthogonal. If i measure position one entangled electron and momentum on other electron for single state then how Heisenberg's uncertainity princple works?? so We may know the both parameter.

In the case of an atom of Cesium ejecting an electron, it would lose one electron from the 6s orbital. The 6s orbital is very high in energy and similarly so would the electron that is ejected from it, right? So if there was a Nitrogen atom as well, how would it be possible that the Nitrogen...

Hi, suppose we have a proton at point A and an electron at point B, at a distance of 1cm , separated by a screen. If we remove the screen one would expect the particles to meet and clash somewhere near point A, but I read this never happens. Can you explain why it's so and what exactly happen...

Dumb question, but something I don't get. I see this expressed in many basic examples of what voltage is. You have 1 object that has too many electrons and 1 object has too little. The potential difference between them is what is expressed as/in volts. If you connect a conductive wire...

Which bulb is really more collisions of electrons inparallel connection? Maybe we can easily get the conclusion about this question. The intensity of bulb's light is depend on the power of electricity(IV), so the upper blub has more number of collisons between electrons and atoms. but I...