The electron is a subatomic particle, symbol e− or β−, whose electric charge is negative one elementary charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron has a mass that is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum (spin) of a half-integer value, expressed in units of the reduced Planck constant, ħ. Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: they can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavelength for a given energy.
Electrons play an essential role in numerous physical phenomena, such as electricity, magnetism, chemistry and thermal conductivity, and they also participate in gravitational, electromagnetic and weak interactions. Since an electron has charge, it has a surrounding electric field, and if that electron is moving relative to an observer, said observer will observe it to generate a magnetic field. Electromagnetic fields produced from other sources will affect the motion of an electron according to the Lorentz force law. Electrons radiate or absorb energy in the form of photons when they are accelerated. Laboratory instruments are capable of trapping individual electrons as well as electron plasma by the use of electromagnetic fields. Special telescopes can detect electron plasma in outer space. Electrons are involved in many applications such as tribology or frictional charging, electrolysis, electrochemistry, battery technologies, electronics, welding, cathode ray tubes, photoelectricity, photovoltaic solar panels, electron microscopes, radiation therapy, lasers, gaseous ionization detectors and particle accelerators.
Interactions involving electrons with other subatomic particles are of interest in fields such as chemistry and nuclear physics. The Coulomb force interaction between the positive protons within atomic nuclei and the negative electrons without, allows the composition of the two known as atoms. Ionization or differences in the proportions of negative electrons versus positive nuclei changes the binding energy of an atomic system. The exchange or sharing of the electrons between two or more atoms is the main cause of chemical bonding. In 1838, British natural philosopher Richard Laming first hypothesized the concept of an indivisible quantity of electric charge to explain the chemical properties of atoms. Irish physicist George Johnstone Stoney named this charge 'electron' in 1891, and J. J. Thomson and his team of British physicists identified it as a particle in 1897 during the cathode ray tube experiment. Electrons can also participate in nuclear reactions, such as nucleosynthesis in stars, where they are known as beta particles. Electrons can be created through beta decay of radioactive isotopes and in high-energy collisions, for instance when cosmic rays enter the atmosphere. The antiparticle of the electron is called the positron; it is identical to the electron except that it carries electrical charge of the opposite sign. When an electron collides with a positron, both particles can be annihilated, producing gamma ray photons.
I am really stuck on what to do here in this question
I have arrived at forming an equation to work out the radius of electron orbit from doing the following
However I do not know what to do next as I don't know what the value of n (quantum number) must be? :oldconfused:
Any help would be...
I know that current chose the way with the lowest resistance but this is becouse that few electrons will go on the two path and the smallest number of electron .,Is the path that the current go throw . But how does a single elelctrons "choose" is path .
And also if I connect two wire to a...
Hello all!
I wrote a reaction mechanism for a sequence that forms an ester. Here is a link to my work:
<Link deleted. See attachment.>
<Moderator's note: please upload all material to PF instead of using external servers.>
Do you agree with my answer?
Thanks for your help!
Have tried doing this question but I'm a bit confused on where I'm going wrong
This is what I have done but get a value that doesn't match to any of the options given above?
Any help would be really appreciated, Thanks!
I know this is a rather weird question but I'm in high school studying physics and chemistry and a lot of the content is pretty basic for what I aim to learn. One topic that I was curious about was electron spins and how that works, because correct me if I'm wrong but aren't they waves of energy...
Following a thread on building a cloud chamber I searched some other sites and encountered some eg. diagrams of electron tracks which puzzled me.
I searched for actual photos and found some very irregular tracks ascribed to electrons, but nothing like these. I can't see how they could arise...
For example, we have this two potencial wells approaching, the electron is confined in one.
the final appearance will be like this:
THEN, if we know a wave packet is formed by many frequencies, but in a potencial well there are just few frequencies allowed, energy levels, so let's say, one...
traditional definition of electron affinity: the amount of energy released by an element in its gas form when gaining an electron
second definition?: the stability gained by an element in its gas form when gaining an electron (e.g. halogens are more stable after gaining an electron, and when...
Homework Statement:: 1. Does the increase in kinetic energy in (for example) water that results from increasing its temperature result from electron excitation (i.e. increasing electron energy levels) or simply increasing their velocity or vibration amplitude/frequency?
2. If excitation is...
Maybe because when you don't observe it, the Schrödinger equation predicts the totality of interactions (paths) of the electron over an infinite time, all the paths it can take ( forming a wave like function ) which is actually all the paths the electron can take overlapped... and when u...
Just wanted to check in my workings to see if they are correct (seemed to be too short to me?)
Since electrical conductivity is 820 (ohm.m) which is = n*e*(mobility)
Mobility =0.17083?
And I can simply get drift velocity by multiplying mobility with an electric field (600V/m)?
Cheers
Hi every one,
In Compton effect I understand that the electron is considered free electron because the energy of the incident photon is very much larger than the binding energy of the atomic electron. But iam not sure why the electron is considered to be at rest (v=0). please help.
Thanks.
Hello! Assume that I have a parallel plate capacitor. If i place an electron close to the negative plate, it will move in a straight line (and accelerate) towards the positive plate. Now, assume that I place a neutral dielectric close to the electron trajectory (parallel to it), say at 1 mm away...
A radiation-shielded go-pro camera was sent through an electron beam irradiator.
You can see the effects that the radiation has on the camera in the video.
I wonder how many rads it was exposed to.
Quick question: let's say we have an atomic electron in the ground state which requires, say, one "unit" of energy* to jump up to the next orbital energy state. If a photon arrives with a bit more or less than this, say 1.00003 or 0.99997 units of energy, is there some finite, non-zero...
Hi all,
I'm right now confused about this.
As far as I know, when changing from a level to another, the change in l (subshell) can only be a difference of 1, and ##m_{l}## can be the same or a difference of 1.
In this case, since the question wants me to state possible quantum states of...
Hi there, popping by here to check my answer because another online platform has already answered it but my answer appears to be wrong. I can't seem to understand why though :/
Since I can find the energy at a state to be ##E_{n}=\dfrac {-13.6z^{2}}{n^{2}}eV##
At ground state where n=1...
Conservation of Energy: 9GeV + E = 5.3GeV + 5.3GeV
Therefore E = 1.6GeV for the threshold energy.
How would I find the velocity of B0 mesons so that I can calculate their mean distance?
Then it would just be distance = velocity of b0 * mean proper lifetime
Right?
Nitrogen has an atomic number of 7. Thus, A nitrogen atom has 7 electrons. Nitrogen’s electron configuration is: [He] 2s2 2p3
The nitrogen element has five valence electrons present in 2s and 2p orbitals. So it would have five dots placed around the symbol for nitrogen.
Is this correct? I need...
how high does a vacuum need to be for electron gun to work? for example, will 1 pascal work, will 1 tenth of a pascal work? is there a minimum vacuum for a electron gun to work?
Homework Statement:: The total energy of the electron in a hydrogen
atom is normally −13.6 eV.
Which one statement below, based on this
fact, is correct?
1. The work required to completely remove
the electron from the atom is 13.6 eV.
2. The electron is in a circular orbit with a
kinetic energy...
Hi,
These questions may seem basic, yet, I do not have an answer for that.
The density of electrons and the density of holes in an intrinsic semiconductor are equal at equilibrium. From this, it seems that holes are simply lack of electrons that are given enough (thermal) energy to escape...
a) since the eletric field is perpendicular to the inicial velocity, the x component is constant, hence Vf.cos45=Vo. This gives Vf=0,6√2.C
b) Ei=γi.Eo , γi=5/4 , Ef=γf.Eo , γf=5/(2√7)
Finally, Ei+e.E.d=Ef. Apparently this is incorrect, why??
Homework Statement:: Consider an electron trapped in a one-dimensional finite well of width L. What is the minimum possible kinetic energy of the electron?
A) 0
B) Between 0 and h^2/8mL^2
C) ≈h^2/8mL^2, but it is not possible to find the exact value because of the uncertainty principle
D)...
I am watching this video;
at the 8:20 mark it shows that a proton in a magnetic field will align with the magnetic field very easily if there is no shielding from electrons, and therefore will require energy to shift to the opposite spin state; makes sense to me. I also understand that when...
I am just asking how fast an electron spins around the nucleus of the atom at lower temperature such as indoors? and at high temp such as explosion or fire?
I know that electricity electrons and energy transfer are much quicker, but I am just asking how fast an electron goes around the nucleus...
dv/dt is the acceleration, so I thought I could find the acceleration from F = qE = ma = dp/dt. But this is a relativistic case, so the proper acceleration is a = F/mγ3, where v in the gamma is the v of the electron and F = eE. However, I'm not sure if this is correct, because the constant τ...
Would this be an accurate portrayal of measuring the spin of an electron with a SG detector?:
The electron is in a superposition of spin-up and spin-down;
Upon entering the magnetic field of the SG detector, the electron enters a superposition of an upward trajectory and a downward trajectory...
It is well known that the 2D free electron gas fermi momentum can be expressed as follows,
k_F=\left(2\pi n\right)^{1/2}
where n is the electron surface density.
Assuming this 2D electron system can be considered as 2-D tight-binding square lattice whose eigenergy can be written as...
Electron in atom at higher level(excited state) of energy has tendency jump to lower level of energy.Then the state of electron is unstale,so there is uncertainty in energy of the electron(the level of energy has a width).What cause the level being a band of energy but not a thin line of...
Summary: How does many worlds deal with the measurement of an electron's position in space?
Hi all - I am reading Sean Carroll's book on quantum mechanics and reached the end of the section on "branching and splitting" without getting an answer. I will lay out my assumptions and then get to...
In this question, I would have to calculate the force in respect to time. However, the question gives me the value of the mass of the electron. In my attempt, I didn't take that into account. I just replaced ##v## with ##\frac{d}{t}## and made the Lorentz force undergone by the particle...
I'm not sure how I'm able to calculate the velocity of the particle using the formula without knowing the force exerted on it. Also, I don't understand why the question also provides the mass of the electron.
Hi, it's been so long since I learned quantum mechanics. So the only thing I can solve now is the square quantum well problem.
But I need help because I have to solve this problem of quantum well.
I tried some calculation but not far.I try to draw the capacitance-voltage profile by drawing the...
I wonder if someone could explain what is known about electron capture in which a proton captures an electron which then becomes a neutron? I have read that a proton which has two up quarks and a single down quark will have the the creation and destruction of multiple quark - antiquark pairs...
This is a multi-part problem. I'm having trouble getting started. Any insights would be greatly appreciated.
Prompt:
To start off with, I think I'm finding the notation confusing. Specifically I'm not sure what U_200 refers to. Some thoughts:
I know that both the potential, and the periodic...
can anyone explain me how O negative and COO negative acts as electron releasing group,I understood how alkyl groups acts as electron releasing group but I can't understand this
How did you find PF?: internet question about electron triplet states
I'm a retired accelerator physicist entertaining myself by trying to understand physics questions like entanglement better. I calculate the expectation value of the product of two electron spins in the singlet state with...
I've been researching the proof of subatomic particles given the fact that we have never seen them before. It has always been recognized that protons, electrons, and neutrons exist; but I question how we know for certain they exist.
Across my studying I've realized that in 1897, J. J. Thompson...
Since electron will stop eventually due to efield,
equation is : ##v^2 = u^2 +2as##
Where v = 0 , u = ##1.04*10^8 m/s##
##a = \frac{qe}{m} =\frac{(1.6*10^{-19})(e)}{9.11*10^{-31}}##
##e = \frac{Q}{4\pi\epsilon(1)}+\frac{Q}{4\pi\epsilon(4-1)}##
Are the equations correct? Or is my concepts wrong?
Addressing to electron as being rigid body that precesse is probably controversial. Are there any attempts to stick to that model and to calculate its quantize tangent velocity?
Is there a radiation method for efficienctly ionizing every electron off of atoms to produce strictly protons and neutrons Without generating tremendous heat?
In a standard kitchen-microwave magnetron, like all magnetrons, a cloud of electrons forms which whizzes around and generates GHz electric currents in an outer ring electrode.
For such a standard kitchen appliance, 800W made with ferrite magnets, what is the typical volume and density of the...
Hi, in the lecture notes my professor gave us, it is stated that, due to Kramers theorem, the energy in a band must satisfy this condition:
$$E(-k) = E(k)$$
But, judging from actual pictures of band structures I don't find this condition to be true. Here's a (random) picture
I guess it looks...
https://ecee.colorado.edu/~bart/book/effmass.htm#short
Looks like the effective mass for holes in Si can either be 0.57 or 0.81, according to the link above.
Is there a temperature regime where one effective mass should be used instead of the other?
Is anyone able to explain in layman's terms...