Electrons Definition and 998 Threads

Is it possible to ID an electron in ATLAS if it did not leave a track in the tracking system? I think that the coverage of the tracker is : ##| \eta | < 2.0## (TRT) or ##2.5## (SCT) for example an event of W+jet would result in Missing Transverse Energy alone + jet if the electron was to leave...

I attached a picture. In the first figure, we see that the difference between bands is rather large. We see that electrons do not occupy all the energy levels from energy 0 to Fermi energy level. There are forbidden band gaps. But in the second figure, I see that the electrons occupy...

Just a thought: The momentum quantum number given for s states is l = 0. If an S state electron dropped in energy, and emitted a photon with l = 1, what would take place? Am I correct that the electron could only drop to a lower l = 0 (an S state) orbital?

before measuring an electrons position, is it physically a smear,like a wave? Or is it just nothing?

Hi. I am struggling to understand the concept of distinguishability in quantum mechanics. If the wave functions of two particles overlap, those become indistinguishable from what I can understand. So if, in an atom, two electrons occupying an orbital are also indistinguishable. right? But can't...

hi every body question is : Consider that 5.5E22 free electrons are confined in a potential barrier of length 3.2A . find its Fermi energy ?the main point is that i was confident about the answer of question .. but the doctor said it is wrong .. he said i should use the relation between the...

All elementary particles, which are not made up by any other particles (electrons, quarks), are said to be zero dimensional and have no size. But why not? Are electrons literally zero dimensional particles with no size?

Homework Statement a)Find the densities of states 0.08 eV above the conduction band edge and 0.08 eV below the valence band edge for germanium. Be careful with units and be sure to give the units for your answer. b) Find the volume density of states (i.e. number of states per unit volume)...

Homework Statement In inkjet printing, a rapidly moving nozzle horizontally squirts drops of ink that form letters and images on paper. A common problem is horizontal white lines running through the print due to a clogged nozzle. Another common problem is paper dust. (a) Within the context of...

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?

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...

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...

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

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?

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?

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...

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?

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...

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...

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...

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...

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...

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...

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...

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?

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...

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...

why would a flame contain electrons and ions??

< 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...

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...

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?

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...

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...

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...

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

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...

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

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...

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...

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...

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...

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...

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?

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...

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...

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 /...

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...

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...

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

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...