Electrons Definition and 998 Threads

My book talks about it, but doesn't give a very intuitive reason why. It essentially says that from a modified version of Liouville's Theorem, the electrons in a band stay in that band. Then it says the phase space (position-wavevector phase space) has a constant density through time, and if...

Does it just burst into vast amounts of energy? Or what about colliding two electrons together. higgs boson?

Hello. You'll have to excuse my spelling (If I spelled anything wrong), I'm from Sweden and even though I'm told to be good at English, I'm not an expert. I literally just found this forum in my search for some kind of physics forum where I could ask the following question: Are electrons...

What would happen if one were to fire electrons at a solid mass of alpha particles?

In chemistry I remember learning that electrons and protons had equal but opposite charges but also that electrons were much smaller than protons. So how is it that something so much smaller can have an equal charge?

Homework Statement My class is currently going over electronic energy levels, and the book states that an electron with a kinetic energy of 9.8eV could excited two mercury atoms (first excited state above the ground state of mercury is 4.9) to their first state above the ground state...

A stream of protons and electrons are shot horizontally (from the left edge of the page to the right) with a speed of 1.2 x 10^6 m/s. A magnetic field is oriented perpendicular to this motion (upward, out of the page) with a magnitude of 1.225 T. What is the radius of the curvature and the...

Hello everyone, I've been told many times that when the right frequency of electromagnetic radiation hits an electron, it is excited to another energy level. My question is this, "why do electrons get excited to higher energy levels when hit by electromagnetic radiation?" Why does the...

Recently there was a discussion concerning whether an electron in the conduction band was localized or delocalized. The back and forth arguments seemed inconclusive, difficult to follow (too brief too couched in jargon/unrealistic models) and ended in something close to insults back and forth...

Homework Statement An electron beam enters the region between two oppositely charged parallel plates near the negatively charged plate, as shown below. The plates are 0.150m long and are 0.040m apart. There is an electrical potential difference of 60.0V across the two plates which creates an...

Greetings, This is basically just an observation I expect it to be laughed at (already has been laughed at in the mensa forum) but you know what they say - the only stupid questions are the ones left unasked and what better way to put it to rest than to ask some real hard core physicists... I...

Hello. I need to find the expectational value of the correlation energy between two electrons which repel each other via the classical Coulomb interaction. This is given by the 6-dimensional integral: \left\langle\frac{1}{|\vec{r}_1 - \vec{r}_2|}\right\rangle...

Since the magnetic force between dipoles goes as 1/r^4 and the electrical force goes as 1/r^2 for charges, would electrons be able to theoretically get close enough for their magnetic attraction to be greater than their electrical repulsion? If so, what then?

in a battery, when all the electrons have transferred to the positive terminal ( i mean both terminals have same no. of electrons) , then do any current flow? if no , then how much time does it take for all electrons to be transferred fron negative to positive terminal? (i know it is a silly...

Homework Statement How many protons are in the beam traveling at the speed of light in the Tevatron at Fermilab, which is carrying 11.17 mA of current around the 6.3-km circumference of the main Tevatron ring? Homework Equations Not sure... The Attempt at a Solution I don't...

physcially, how electrons choose the path with min resistance if 2 paths of 2 differnet resistances electrons distributed & may if short circuit exist it take it how electrons know there is short circuit and how they know the path of min resistance ! Another question of a connection...

Homework Statement When an electron moves with a certain de Broglies wavelength, does any aspect of the electrons motion vary with the wavelength. Homework Equations λ=h/p p=mv The Attempt at a Solution Ok so I realize that under certain conditions electrons wavelike properties can be...

I am trying to draw electron configurations for multivalent electrons for Pb4+ and Pb2+. The work I have: (Xe)6s24f145d10 (PB2+) (Xe)6s04f145d10 (PB4+) the problem I'm having with multivalent structures is: I have no idea which electrons to remove when there is an ionic charge For...

Homework Statement Determine the number of K electrons ejected from a foil of lead with thickness 0.5 x 10^20 atoms/cm^2. It is bombarded by 10^4 photons that each have an energy of 88keV. Homework Equations From a figure in the book, it shows that u/p (7.483 cm^2/g = .7483 m^2/kg). I...

How do you find the number of unpaired electrons in a salt such as aluminum sulphate or ferrous sulphate. The number of unpaired of electron or bond order is needed to determine if something is paramagnetic.

Ok, I've been reading up on the EM field and how it exerts force on charged particles. By exerting this force it creates 'ripples' in the EM field and this is felt by other charged particles as a force (either of attraction or repulsion). We say that the two particles exchanged a virtual photon...

So i was watching Susskind lectures on entanglements http://www.youtube.com/watch?v=CaTF4QZ94Fk and there he mention decay (electron in magnetic field emits a photon whit certain probability ) That made me wonder : 1. How long you have to wait for emission to occur ? (for probability of...

Homework Statement Take a look at this image first If two electrons are each 2.50×10−10 from a proton, as shown in the figure, find the magnitude and of the net electrical force they will exert on the proton. Homework Equations The Attempt at a Solution k=1/4πε0 So what...

Homework Statement If there are 13 electrons in M shell and one electron in N shell, the the number of unpaired electrons in such atom will be Homework Equations M- shell N- shell The Attempt at a Solution The configuration should be 3s2 3p6 3d5 4s1 hence the answer should be 6

Can we give an analogy for nucleus to sun and electrons to planets...... Hi all, Can we give an analogy for nucleus to sun and electrons to planets...... like this in several galaxies... and galaxies together form some other material in larger scale. Also can we say wave nature of...

Hey guys I'm a new member and I will be mostly asking questions :P Anyways ... Physics subjects in my school are about electricity now and my teachers aren't very good, so I can't clearly understand what they're saying. To get to the bottom line, our lesson was about electrons and...

Off the Wikipedia: "...in a copper wire of cross-section 0.5 mm2, carrying a current of 5 A, the drift velocity of the electrons is on the order of a millimetre per second." Suppose we have a setup with a very very light wire which can transmit very very high currents. Once the current is...

Im wondering how potential can act as a boundary for electrons in a 1-D time independent infinite well?

Consider the simplest of all possible atoms: A hydrogen atom with only a proton as its nucleus. According to QFT, the electron is constantly exchanging photons with the proton. So, are the electron and proton entangled? Thanks in advance.

Why must we apply the Pauli Principle to electrons in a metal? Do they share a many-body wavefunction? The saying is that no two electrons may occupy the same state, but am I allowed to say "well, this electron is at the top of the metal, and there is another one at the bottom, those two are...

Homework Statement If each orbital can hold a maximum of 3 electrons, the number of elements in the 4th period of long form of periodic table will be? Homework Equations ? The Attempt at a Solution I am not able to decide from where should I begin?

Homework Statement Hello. I have an exam soon so I need to do many exercises. I have a problem with one. I need to get an acceleration of electrons in lamp which energy is 14 000 eV and magnetic induction is B = 5.5*10^(-5) T. The Attempt at a Solution The correct result is...

Homework Statement When the frequency of light incident on a metallic plate is doubled, the K.E. of the emitted photoelectrons will be? Homework Equations The answer should be either doubled or increased but more than double of the previous kinetic energy The Attempt at a Solution λ=...

Dear Physics Forum, I wanted to know if there is any theory of elementary particles that explains why protons, neutrons, and electrons assemble into atoms? When these particles were first made in the Universe, why do the assemble into atoms? For example, why don't electrons simply bind...

electrons -- Relativistic velocity addition... Homework Statement an observer measures the velocity of two electrons, finding one with a speed c/2 in the x direction and the other c/2 in the y direction. what is the relative speed of the two electrons. Homework Equations The...

Couldn't decide where to post... Chemistry or quantum mechanics... But posted here cause I wanted to know a physicist's view... We know that the electrons in the atom have discrete energy,I mean not just any energy... An electron can't have the energy between 2s and 2p orbitals... But after...

Homework Statement A parallel-plate capacitor is charged to an electric potential of 100 V by moving 4x10^19 electrons from one plate to the other. How much work was done? Homework Equations How much work was done? The Attempt at a Solution Work is then simply equals to...

What prevents the electrons from hitting the nucleus? Shouldn't the proton attract it and destroy the atom?

At zero kelvin,are there free electrons? At zero kelvin,the free electrons should have ZERO energy.But they are able to move under the influence of a electric field? But when they are attracted towards the positive potential shouldn't they gain K.E? So they are moving at zero kelvin?

In the double-slit experiment, without which-path information available, the diffraction pattern is usually shown as an even function with respect to the displacement from the midpoint of the slits: something like sin ay / y. (This is the case in Feynman's lectures, and many others.) The...

Homework Statement Two metal plates, PQ AND RS are separated by a distance of 15 mm. PQ maintained at potential of +100V relative to RS. Beam of electrons of different kinetic energies directed a slit ,on plate PQ, at angle of 60 degrees to plate. To find the K.E of electrons that 'just'...

Hi All, Protons repel each other and in order to make them collide in the LHC huge amounts of energy have to be put in place, my question is; if we launch a beam of electrons transversal to the beam of protons and right in the collision point of the protons, would not this increase the energy...

Do ions have a measurably different rate then their neutral counterpart or does the rate of radioactive decay and electrons have no correlation? Also, when a source states an elements half life is that the same for all of its isotopes?

Hi. I would like to know if the results of the observations of electrons passing through double slits needs to be observed by a person for the electrons to act like theyve been observed? Or, is the equipments observation of the electron is enough for it to act like its been observed...

I was just reading R.Feynman's Lectures on physics Vol I and I came across this discussion in which he says that magnetic field results from an electric field i.e relative motion of electrons and so on. Further, he says that the electomagnetic spectrum consists of light waves... The whole...

Hi. I'm currently working through Griffith's Introduction to QM, and have gotten to the section on the periodic table. I'll explain my understanding a little bit... Before this he's been looking at the Hamiltonian for helium: H = \left[ \frac{- \hbar ^2}{2m}\nabla _1 ^2 - \frac{1}{4 \pi...

Do electrons flow in a "circuit" in a CRT? When they hit the phosphor coating on the screen, does the final anode complete the circuit and allow current to flow back to the circuitry or does the anode only serve to accelerate the electrons which then "accumulate" by combining with the phosphors...

Homework Statement So i know the light colour, wavelength, cutoff potential and frequencies. I am trying to find the maximum kinetic energy of the ejected electrons(J or eV) heres the first set of numbers for the colour of yellow: wavelength 578nm(5.78 x 10 to the -7metres). cutoff...

attraction -- why do electrons and protons attract each other? Hi, why does electrons and protons attract each others? This happen with other particles too (photons, neutrino etc..) ? thanks

If bubble chamber tracks are formed by charged particles leaving a trail of ions as they pass through, by knocking electrons out of atoms, then why aren't there spirals of electrons along the whole track? Also, are the straight lines in bubble chamber photographs actually curves of a very...