Electrons Definition and 998 Threads

I know that sufficiently energetic protons and photons (1.7MeV) can knock a neutron out of a beryllium nucleus. Can an electron do the same?

As the title suggests. What is the space between the nucleus and electrons of an atom? Thanks

Is this correct? “The force that gets the electrons moving is the electric field. In AC, it is actually an electromagnetic wave traveling along the wire. Note that the electrons not only react to the electromagnetic field, but also are sources; the oscillating electrons themselves emit...

When we first learn of selection rules for atomic transitions, we learn that electrons have to change between states that differ in angular momentum by at most 1ħ, because photons have 1 unit of spin angular momentum. However, photons can have arbitrarily high integer quantities of orbital...

why do electrons revolve around the nucleus?

Hello, I have a questions regarding the double slit experiments using an electron beam. If I understand correctly, in the back measuring plate you will see little tiny dots of electrons colliding; however, the pattern exhibited will be similar to that of the one seen in a wave-like experiment...

So I was watching TV and I got to thinking. If a hydrogen atom has 1 proton and 1 electron... What element would you make if, instead of adding protons and nutron to the nucleus, you were to somehow add additional electrons to the orbitals of that single proton? Is it even possible and what...

Are electron also wave as are photons. I can image electron as Gaussian pulse to preserve it dual particle-wave nature. Does it preserve own magnetic and electric field values and wave frequency?

I have heard that instead of orbiting the nucleus they actually pop into and out of existence around the nucleus forming the electron cloud, and where they relocate depends on the probability of that area due to wave function, am i right?

Does the Copenhagen interpretation allow for particles(electrons) to be in more than once place at the same time. I am not talking about quantum superposition here. I'm asking if it allows for electrons to be in many places at once like the many worlds interpretation does.

Homework Statement A slab beam of electrons of thickness a, width w >> a, charge density (-ρb ), (Take ρb to be positive.) and velocity vbez passes through a channel of neutralizing ions with charge density f*ρb where f is some number between zero and one (all parameters given above apply in...

I was reading my physics books. And then a question came across my mind. Now here the the definition of coulomb. Electric charge measured in units of coulombs. It takes about 6*10^18 electrons. So the question is did the electric charge only consists of electrons.

I was wondering if protons and electrons have different description in the terms of quarks if they're in Dark Matter??

Homework Statement There's an engine connected to a battery with a copper wire. ρ = 1.69x10^-8 n = 8.49*10^28 electrons/m^2 The diameter of the wire is 5mm. The length is 1m. How long does it take for an electron to go from the battery to the engine if i = 100A? Homework Equations ## v_d =...

So electrons were suppose to crash on nucleus according to classical physics. I want to understand the dynamics of it. The basic idea is that it will slow down as it emit photons. But with what force and mechanism? I think the answer is related with Abraham-Lorentz force, but i see too many...

Why are electrons generally further out than protons in the Van Allen Belt?

Homework Statement Two electrons are held at rest 0.05[cm] apart. what is their relative velocity when they are 1[cm] apart. Homework Equations The potential V from a point charge: ##V=K\frac{q}{r}## The constant ##K=9\cdot 10^9## The work done to move from one point in the field to another...

The n = 2 energy level of lithium is 108.8 eV away from the n = 1 energy level. Does that mean, in a DC circuit, that if you put an emf of 108.8 V along a lithium wire, that the high voltage will excite an electron to the n = 2 level?

Lets take a simple water molecule for example. You can use the photoelectric effect to remove electrons from a molecule. As a thought experiment, let's say you have a contained single water molecule in a vacuum with no impurities. Perfect Vacuum. If you use the Photoelectric effect and beam...

know benzene is colourless...but i can't seem to get my head around it at the moment! As benzene has delocalised electrons, it should require less energy to excite the electrons. And Visible light is a lower frequency to UV? So according to the equation: E=hv Benzene should be coloured as it...

The force in the Casimir effect can be "explained" by two causes, see, http://en.wikipedia.org/wiki/Casimir_effect#Possible_causes In some optics experiments we must account for the fluctuations of the quantum vacuum to get the right experimental results. See, Vacuum noise...

1. There are 2 negatively charged plates opposite each other. In between them, there is a vacuum tube (50 cm long), containing only 1 electron. Assume it is completely isolated. The charge value for the plates is equivalent to 10000 electrons. Initially the single electron is directly in the...

When the beam of electrons reflect back to the grid due to the repeller voltage in reflector plate ,how the grid decelerates the returning electrons ?? And how they release their energy to the grid ?

Hi there, I would like to ask is it possible to calculate the min. voltage to initiate the spark gap create by the Jacob's Ladder and also the max. distance between two rods to make the spark gap "jump"? Other than that, is it possible to calculate the no. of moles of electrons...

For the fermi dirac distribution function for temperatures higher than 0 K, how do we approximate the number of electrons available for conduction?

If you have a still wire with electrons moving through it, to an outside observer at rest relative to the wire, would the space between the electrons contract? I would think that special relativity causes the electrons to contract, (not the space between them) but the contracting of the...

Homework Statement The emission spectrum of thermally excited sodium atoms practically consists of a single intensive line at 589 nm wavelength. What is the energy difference (in eV units) between the excited and ground states of the sodium atom? Homework Equations E = hc/lambda, we also know...

Hi, so I'm a first year neuroscience student at Carelton University in Canada. I had a little bit of a "revelation" with this topic recently after I understood it a bit better and I think this is really interesting. (If I understand it correctly!) We're learning about Kekule structures...

Homework Statement An electron with a speed of 5.0x10^6 m/s is injected into a parallel plate apparatus, in a vacuum, through a hole in the positive plate. The electron collides with the negative plate at 1.0x10^6 m/s. What is the potential difference between the plates? Vi= 5.0x10^6...

Homework Statement In classical electromagnetism, an accelerated charge emits electromagnetic radiation. In non-relativistic limit, where the velocity of the electron is smaller than c, the total power radiated is given by the Larmor formula, to wit P=2/3*e2*a2/c3, where a denotes the...

Homework Statement I am attempting to solve a question which asks the carriers in Ag. Homework EquationsThe Attempt at a Solution Is the use of the word 'Carriers' simply another way of saying excited conduction electrons? Thank you.

I would like to ask what does mean energy distribution ,and how can I calculate the energy distribution of transmitted electrons . Thanks

Well, when 2 atoms get close, we don't feel the touch between them but the forces between electrons. So what will happen if there's atom with no electrons, so any other atom with electrons will be able to really "touch" it( because there would be no force between electrons). What will happen then?

Hi, I want to calculate the position-wave-function of a system of two free electrons with momenta k1 and k2 (vectors). 1. Homework Statement So, I want to have Psi_(k1,k2)(x1,x2) for a state |k1,k2> I also know that <k'|k> = (2Pi)^3 Delta(k-k') The Attempt at a Solution I tried the...

An atom has an equal amount of positive and negative charges. But those charges are not all in exactly the same spot. Electrons are closer to other atoms than the protons are. So, would a lone positive charge be attracted towards the electrons in an atom?

I've been reading lately in particle accelerators and electrons and it got me wondering. How do electrons induce resonance in a cavity resonator? Do they have to first be accelerated to one of the walls of the cavity where they then bounce off toward the other wall?

Homework Statement (a) the density of k-states g(k) = L^2*k/2*Pi. (b) the density of states g(E) = L^2*m/Pi*h^2 (c)The density of states per area n2D(E)=m*/Pi*h^2 (d) Sketch a graph of n2D(E) vs E. (e) Calculate n2D(E) as a quantity. The questions don't have to be answered in full a...

So I have seen some people doing making lichtenberg figures using a particle accelerator to blast electrons into a dielectric where they get stuck until the dielectric breaks down. Here is an example http://www.capturedlightning.com/ Are there other ways to get electrons into a dielectric other...

Homework Statement Here is a picture: http://puu.sh/bZtAu/82bdc201bc.png Homework Equations For force, F = (Ze^2)/4 * pi * e0 * R^3) * r f = sqrt(k/m) * 1/2pi Where e0 = vacuum permeability, 8.854 x 10^-12m and r = radius of hydrogen atom, 5.3 x 10^-11m The Attempt at a Solution I...

what is the technical meaning of refocusing paraxial electrons along the direction of magnetic field?

Homework Statement The UV/visible spectroscopy of linear conjugated molecules, particularly 1,3-butadiene in this problem, can often be modeled with the Particle-in-a-box of the electrons. Assume that we are interested in the pi electrons ONLY. A molecule with N double bonds = 2N pi electrons...

As an engineer I was interested in the setup of the experiment described in '1-6 Watching the electrons' of Feynman's recently published lectures. I understand that a method that is used to detect whether the 'particle' passes through hole 1 or 2 is to use a wave of a wavelength that is either...

Hi http://uw.physics.wisc.edu/~himpsel/551/Lectures/E_versus_k.pdf Look at first picture If you see this picture of a bloch wavefunction, you see that it has two types of periodicities involved, one with the lattice constant(the bloch part), but what is the periodicity of the enveloppe. Has...

Tests of layered tiles of carbon nanotubes packed with gold and surrounded by lithium hydride are under way. Radioactive particles that slam into the gold push out a shower of high-energy electrons. They pass through carbon nanotubes and pass into the lithium hydride from where they move into...

Hey guys, I'm having some trouble figuring this part out, so I've done most of this problem just can't figure out this part...so here is the question. (Sorry in advance as I don't know how to use LaTeX on here). What is the distance Δy between the two points that you observe? Assume that the...

How can I find the number of protons and neutrons of any element without looking the periodic table. And I need them each so mass spectrometer won't work Edit: I noticed that my title is wrong, explanation of the number of electrons are not needed

Do high voltage means high speed of electrons

Homework Statement For an electron in a uniform magnetic field, say B\hat{z} with no angular momentum, the Hamiltonian can be expressed as \hat{H}=\frac{1}{2m}\Big(\hat{p}_x^2+\frac{mω^2}{2}\hat{x}^2\Big)+\frac{1}{2m}\Big(\hat{p}_y^2+\frac{mω^2}{2}\hat{y}^2\Big) Which is equivalent to two...

I'm creating a simple model of a quantum tunnelling composite component (google for details). Most of the model is simple enough, but I can't think what would happen to the electrons that don't tunnel, as an electron build up would cause current to decrease with time as the plate becomes more...

The problem is to apply Schrodinger wave equation to a beam of mono energetic electrons and show that the probability of finding electron at each point on the beam is constant (d2ψ/dx2) + (8∏^2m/h^2)(E-V)ψ = 0 I have been taught to apply this to a single particle for various...