Electron Definition and 999 Threads

The electron volt can be defined as mass, temp and energy. 1 eV = 1.6022 x 10-19J 1 eV = 1.783 x 10-36kg 1 eV= 1.160 x 104K How can something with such small energy and mass exhibit such high temperature? 104K is white hot

If w3e fire electrons thru the 2 slit we get an interference pattern showing the wave nature of the electron. Now if we cover one of the slits and fire electrons we get a bar like pattern on the screen. If we cover one slit, fire electrons and use a detector we would also get a bar like...

Homework Statement A 0.7MeV (E°) photon scatters off a free electron such that the scattering angle of the photon is twice the scattering angle of the electron (θ=2φ). Determine the scattering angle for the electron. Homework Equations λ' - λ° = h/(mec)(1-cosθ) E = hc/λ ρelectron = mev /...

[Mentor's Note: The first 4 posts have been split off from another thread.] I want to know why a electron has a different charge than a positron. lets use an electron and positron that came to be at the same time and place. They should have split something. Can someone explain what it is they...

At room temperature, particle energy is 0.025eV. Neutron capture reaction has big cross section when neutron is in room temperature. Theoretically, so does an electron. At 0.025eV, the electron velocity should be only 93.78km/s. Unfortunately almost no way to cool down an free electron to so...

So I was wondering... for no particular reason: Say you have a proton and your right arm is a particle accelerator. You throw the proton at about 90% the speed o' light. The you take your left arm which also happens to be a particle accelerator and you shoot an electron out right next to it...

Hello, I have a 12 pin Photomultiplier tube and am wondering how many ohms should be on the resistors. There would be 11 resistors (1 between each pin) and no capacitors, anode grounding for DC operation, 1000volts, only to go off to an op amp for signal processing. This design is shown in...

Homework Statement Predict the number of unpaired electrons [Cr(H2O)6]3+ Homework EquationsThe Attempt at a Solution I under stand how to fill out the MO with the eg and t2g and all but I'm confused about determining the number of electrons. The answers state this is an octahedral d3 but I...

I know an electron is constantly flipping between two quantum spin states. I know that one spin takes slightly more energy than the other and it gets and drops this energy into and from the Higgs field, which gives it mass. The default behavior of all particles is to travel at the speed of...

I understand that in an electrical circuit, a positive test charge will gain electrical potential energy when moving from the negative to positive terminal of a battery (as it's moving against the electric field); it will then naturally flow around the circuit back to the negative terminal as it...

hi, so my lecturer decides to give me manic depression by sending me on a wild goose chase. what is the general form of a plot of Ψ, Ψr2 and r2Ψ versus r for both Ψ2s and Ψ2p orbital... am not even sure i said it right So far I have only gotten the Ψ2r2 versus r

This is not a normal problem help topic. The difficulty I've encountered is in understanding an alternative solution. 1. Homework Statement In a real conductor, electrons (with mass m), conducted by external electric fields, constantly collide with defects and impurities within the conductor...

Can anyone suggest me a book on quantum electrodynamics for beginners? Thanks in advance

So a programme that I watched on tv was talking about neutron stars and they said that the neutron stars neutrons were formed by protons and electrons combining to make neutrons. I was just wondering, how does this work, in the field of the quarks in the proton and how they are effected by an...

A beam of electron in vacuum with velocity v enter a region of spa e with a electric field E. The field is such the electrons circle with radius r. The electrons are now accelerating at constant tangential speed. Because this is not an atomic orbital then by classical physics the electrons...

Why is it easier to remove an electron from p orbital than s orbital. I thought P orbital have higher energy so more energy is require to remove a electron from P orbital.

What do we mean when we say the energy of electron in stationary state is given by an equation from bohr's model of hydrogen atom ?

Why does the energy of an electron does not change with time ?

I am trying to find the DeBroglie wavelength of an electron moving at .8c. I have never learned special relativity but I believe the momentum is affected (mass change). I used the formula p= (mv)/(1-v^2/c^2) and got a momentum of p = 2.733 E-22 and a wavelength of lamda = 2.4149 E-12. Did I...

Homework Statement Consider the electronic configurations [Ar]3d94s1 and [Ar]3d10 for an atom. (a) Identify this element. (b) Use Hund’s rules to explain which is the ground state. Show your work for full credit. Homework Equations J=L+S n2S+1LJ L= l1+l2 S= s1 + s2 or S = (1\2)* number of...

Homework Statement An electron has an initial velocity of 5.00 x 10^6 m/s in a uniform 2.00 x 10^5 N/C strength electric field. The field accelerates the electron in the direction opposite to its initial velocity. (a) What is the direction of the electric field? (b) How far does the electron...

We can deflect a moving electron using an electric field or using a magnetic field. In order to obtain the same deviation, when the energy we should use is higher? Or, in other words, the "electric" or the "magnetic" property is stronger?

Hello, I am trying to figure out the width of bands in a 1-dimensional lattice. Here is a short derivation from the book I am reading: if we approximate the free electrons as being in a square well then the energy levels are ## \frac{\pi^2 \hbar^2 n^2}{2mL^2}##. If there are ##N## ions...

Homework Statement An electron in a finite square well has 6 distinct energy levels. If the finite square well is 10nm long determine: a) Approximate the possible values for the depth of the finite square well ##V_0##. b) Using a well depth value in the middle of the results obtained from part...

My quantum textbook says that the probability of finding an electron in a 1s orbital between r and r+dr is given by Prob = (4/a^3)*(r^2)*exp(-2r/a) dr. In this case, Prob(0) = 0 because of the r^2, which is part of the volume element in spherical polar. Does this mean that it is impossible to...

I don't know where I'm going wrong with this problem - I was so sure I had it right but the online grader tells me otherwise :oldfrown: Homework Statement An electron in a one-dimensional box has ground-state energy 2.60 eV. What is the wavelength of the photon absorbed when the electron...

Homework Statement How many orders of magnitude smaller is the average drift velocity of a hole than the RMS thermal velocity of an electron moving in free space? (Use the law of equipartition to find the RMS thermal velocity of a free electron.) This is the last part of the problem, I have...

Why electron and overall an atom is most stable in lowest potential energy? There is a concept of stable equilibrium in classical physics, does it apply here as well? but electron is never in an equilibrium state, neither an atom is. Then why it tries to be in lowest potential?

Homework Statement An electron travels at 0.422c. Calculate the following. (a) the relativistic momentum kg · m/s (b) the relativistic kinetic energy J (c) the rest mass energy...

Homework Statement Show that the scatter angles of the photon (θ) and electron (Φ) in the Compton effect are related by the relation: ##cot (θ/2 )=(1+\frac{hf}{mοC^2}) tan(Φ) ## Where f is the frequency of incident photon 2. The attempt at a solution I wrote down the equations of conservation...

This has always bugged me, but it appears that the answer is out there via this: "But deep theoretical reasons having to do with the rotational symmetry of nature lead to the existence of spins for elementary objects and to their quantization." The sentence before says this: "A simple answer...

Can an electron absorb a photon and jump to a higher orbit if the next level is already full of electrons? please explain what happens and also link info that might help me with electron/ photon interaction. I have many questions. Thanks

The question also wants a numerical answer, calculate the amount of energy released. I am helping my friend with this because she is bad at science, but she is in College. If anyone knows of any formulas that would be of use, i would appreciate it.

Homework Statement a) An electron is trapped in a one-dimensional box that is 526 nm wide. Initially, it is in the n=2 energy level, but after a photon is absorbed the electron is in the n=7 energy level. What is the wavelength of absorbed photon? b) Eventually, the electron ends up in the...

Homework Statement This is problem 5-42 from Modern Physics by Tipler & Llewellyn. Neutrons and protons in atomic nuclei are confined within a region whose diameter is is about ##10^{-15}##m. At any given instant, how fast might an individual proton or neutron be moving? Homework Equations 3...

The problem: A beam of electrons with kinetic energy 12.8 eV collides with a hydrogen target. What visible spectral lines will be emitted due to collisions? My question: I am confident I know how to do the bulk of this question, I am just uncertain about one thing: I know that 12.8 eV is enough...

Homework Statement Hi! I need to solve a continuity equation for electron density as a function of time in the E-region of Earth's atmosphere. I shall neglect vertical transport and that the ion production rate completely shuts off dusk. Homework Equations See below The Attempt at a...

The probability distribution of the position of the electron of a hydrogen atom is related to the following polar plots Suppose the electron is excited from the ##1s## orbital to the ##2p_x## orbital. Does it make sense to talk about the ##2p_x## orbital having a dumbbell shape pointing in...

Homework Statement An exercise examining the tin atom (Sn). Tin has a ground state electron configuration of ##[Kr]4d^{10}5s^25p^2##. a) Write down the electronic configuration of the first excited state. b) Illustrate with a vector diagram the allowed total angular momentum ##J## values for...

In a covalent bonded molecule, what is the force responsible for the molecule staying together. To my knowledge it's to do with electrons of opposite spins and being at a lower energy with valence shells filled but what is the force itself that pulls a second atom along if the atom it's bonded...

Just a quick question. We know that an accelerated electron shoots out light, and light that falls on an electron in an atom, excites it. But what happens to an electron in vaccum, when it encounters a laser beam? If an electron beam from an electron microscope, were to to intercept a laser...

Question in my textbook:- The wavelength of light from the spectral emmision line of sodium is 589 nm. Find the kinetic energies of electron and neutron at which they both have same de broglie wavelength. Logically, since light of same energy is falling on both then their kinetic energies must...

Moved this question from the quantum physics section to this section, since... Well it fits this section better since electrons apparently do obey conservation of momentum in the 'classical' sense. Why not produce thrust in microgravity with electrons? Plenty of harnessable electricity in...

Electrons have a theoretical rest mass. They can move at varying speeds through space, unlike photons. They ehxhibit quantum-characteristics in their behavior. If an electron collides with, say, an atom, does conservation of momentum apply in the classical sense or does measurable mass (an atom...

The charge of an electron is -e in energy scales well into the atomic scale. At infinitesimal scales it becomes infinite. This relation must be continuous for re-normalization to work, thus the intermediate value theorem asserts that it attains all values between at some energy level. I want to...

i am just a student who wishes to learn more about physics and the way the universe works, but because i am 14 and am just starting to learn all of this on my own i have to start from scratch, please present me with any usable information

Homework Statement My book is saying that if a nucleus has too many neutrons beta minus decay or electron capture is going to happen. The nucleus wants to get rid of a neutron so it is going to send out one electron and an antineutrino that originally comes from the neutron. But what I don't...

Homework Statement Photon of energy E=0,3MeV is scattering at an angle \phi=\frac{2\pi}{3}. Calculate the energy E' of scattered photon and emitted electron. Homework Equations -Compton effect The Attempt at a Solution By Compton effect...

Hi All, Having difficultly figuring out where I've gone wrong with this problem. Any guidance gratefully received. 1. Homework Statement A 4.76 keV electron (an electron that has a kinetic energy equal to 4.76 keV) moves in a circular orbit that is perpendicular to a magnetic field of 0.392...

Homework Statement Hi! I really need help with finding time- dependent continuity equation for electron densities in the atmosphere. I've tried to solve it without any success. My question is if someone can give me a good link/link or equations that I can start with. Homework Equations See...