Atom Definition and 999 Threads

The equation $$\frac{\hbar^2}{2m}\frac{d^2u}{dr^2}-\frac{Ze^2}{r}u=Eu$$ gives the schrodinger equation for the spherically symmetric functions ##u=r\psi## for a hydrogen-like atom. In this equation, substitute an assumed solution of the form ##u(r)=(Ar+Br^2)e^{-br}## and hence find the values...

In Sheldon Glashow's critical review of "What is Real? The Unfinished Quest for the Meaning of Quantum Physics" by Adam Becker, there is one paragraph I don't understand. In Glashow's thought experiment of a single radioactive atom in a box: My thought experiment is like Schrödinger’s, but...

Reading the classical Feynman lectures, I encounter the formula(19.53) that gives the radial component of the wave function: $$ F_{n,l}(\rho)=\frac{e^{-\alpha\rho}}{\rho}\sum_{k=l+1}^n a_k \rho^k $$ that, for ##n=l+1## becomes $$ F_{n,l}=\frac{e^{-\rho/n}}{\rho}a_n\rho^n $$ To find ##a_n## I...

When we say energy levels of the hydrogen atom. Are that energies of the atom or of an electron in the atom? Also corresponding states? http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/hydwf.html Why energies are negative? E_n \propto \frac{-1}{n^2}

Can someone explain me conceptually how one can use trapped ions to make atomic clocks? My basic understanding of trapped ions is, we can think of an ionized atom which is controlled by electric and magnetic fields. But i am wondering how can one build an atomic clock using trapped ions.

We usually think about atomic orbital as wave(function), but it was created from e.g. electron and proton approaching ~10^-10m (or much more for Rydberg atoms), and electron has associated electric field. This wavefunction also describes probability distribution for finding electron (confirmed...

Hello,everyone. Can dynamical system be used to describe the behavior of the electron in Hydrogen atom?

This question is a followup to another thread. https://www.physicsforums.com/threads/qs-re-the-behavior-of-atoms-after-decoupling-completed.994581/ I would like to explore the issue raised by @kimbyd. . . . after reionization the temperature of the intergalactic medium is dominated by...

I am trying to solve the following exercise. In a H atom the electron is in the state described by the wave function in spherical coordinates: \psi (r, \theta, \phi) = e^{i \phi}e^{-(r/a)^2(1- \mu\ cos^2\ \theta)} With a and \mu positive real parameters. Tell what are the possible values...

When solving the Schrodinger equation by separation of variables to atom with one electron and in the spherical coordinates, we get $$\Psi = \Theta(\theta)\phi(\varphi)R(r)$$ Specifically, $$\phi = e^{im\rho }$$ The question is, why we adopt this particular solution, in general, we have this...

I have a neutral charged atom. When I bring an electron to this atom what the force will hold this electron with neutral atom?

Hello! I want to make sure I understand (mainly qualitatively) what happens to an atom in a magnetic field. Assume we have an atom with an even number of protons and electrons. This means that all proton (electrons) are paired up, except for one of them (I am not totally sure if this pairing is...

The question is like this: The solution is like this: However, according to the equation for ##E_{dip}## , what I think is that it should be: $$E=\frac {1}{4 \pi \epsilon_o} \frac {qd}{d^3} \hat {\mathbf z} $$, where I take the centre of the sphere in figure 2 as the centre of the...

[ Wikipedia quote ] Georges Lemaître first noted in 1927 that an expanding universe could be traced back in time to an originating single point, which he called the "primeval atom". Exactly what did Georges Lemaître do? What did he suppose? What did he solve? Did Lemaître think the universe...

a. This is easy with ## q = n*e ## ## 3.2 * 10^{-9} = n * 1.6*10^{-19} ## ## n = 2*10^{10} ## electrons b. Total Lead atoms are ## \frac {8 * 6.022*10^{23}} {207} = 2.3 *10^{22} ## I used the Avogadro number. Total electrons = ## 2.3 * 10^{22} * 82 = 1.88 * 10^{20} ##, here i multiplied with...

First of all, I got to decide what I'm going to use to make the simulation. I know Fortran, Matlab etc but I'm pretty sure these won't help me much. I learned some C++ a couple years ago but my knowledge is rusty, however I think I'm going to use that combined with Unreal Engine, since it makes...

What will happen if somehow we make electron to stop revolving around the necleus?

Good day, I have a question about breaking an atom down in it's components. For an example we have a neutral 4-helium atom. The helium atom have a nucleus which contains 2 protons and 2 neutrons. Around the nucleus of the helium atom 2 electron orbits in the k-shell (according to Bohr's...

My textbook says "A is the area of the circle enclosed by the current" (produced by an electron in a hydrogen atom), A = ##\pi r^2 \sin(\theta)^2##. I don't understand where the ##\sin(\theta)^2## comes from.

I am unable to complete the first part of the question. After I plug in the function for psi into the differential equation I am stuck: $$\frac {d \psi (r)}{dr} = -\frac 1 a_0 \psi (r), \frac d{dr} \biggl(r^2 \frac {d\psi (r)}{dr} \biggr) = -\frac 1 {a_0}\frac d {dr} \bigl[r^2 \psi(r) \bigr] =...

Hope someone can help!

I just want to confirm something. You need about 13.6 eV of energy to ionize a hydrogen atom in the ground state. Can the atom absorb a photon with 15 eV of energy? I think it can. This would free the electron, and the freed electron would move off with a kinetic energy of 15 minus 13.6 eV...

I can not solve this problem: However, I have a similar problem with proper solution: Can you please guide me to solve my question? I am not being able to relate Y R (from first question) and U (from second question), and solve the question at the top above...

This is a general property of eigenvectors of Hermitian operators. State functions are a particular class of vector, and it is easiest to work in the general formalism (I am hoping to show how ket notation makes qm easier, not just do standard bookwork at this level). Suppose O is a Hermitian...

I would like to see what the shape of the ground state radial wavefunction for the Lithium atom is. An approximate function that shows the shape would be fine. Thanks.

Do they mean something like this?

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...

Why energy of the electron in ground state of hydrogen atom is negative ##E_1=-13,6 \rm{eV}##? I am confused because energy is sum of kinetic and potential energy. Kinetic energy is always positive. How do you know that potential energy is negative in this problem?

Hello folks, I've managed questions (a) and (b) but don't get what to do with part (c). Normally you would equate the velocity equations v2=e2/4πεmr=(n2h2)/(m2r2 ). This let's you isolate the radius and use it to calculate En. But I can't see how you could do this for v given in (a) and (b)...

If thermal motion (collision of atoms) changes the direction of an atom, will that change the direction of spin? If so, how much time does it take from the change in the atom orientation to the change in the spin?

Resources I have looked at distinguish between the three basic states of matter in terms of how closely particles are held together; i.e. in solids they are bound most closely, in liquids less so and in gases they're much freer. Would it not be more correct to refer to how closely atoms or...

Some sources say that Democritus named the atom 'atomos', which means 'indivisible', back in 430 BC. Other sources say that John Dalton named it in his atomic theory. Which is true?

We are taught that light travels in stright lines when ever it can. My question is when a photon has left its captive atom how does it know which way is straight?rm

Like the title says: which factors play a role?Also, why do some (unstable) atoms emit alpha-particles, while others emit beta- or gamma-particles/radiation?Thanks for any insights!

Considering an atom,It is feasible to model the electrons as orbiting the nucleus, but this model has drawbacks.Is it feasible to model the associated virtual photons of the nucleus as orbiting the nucleus?i.e.As light travels at velocity c, then this would be the orbit velocity around the...

Hello,In one simple model of the hydrogen atom, the tangential speed of the electron in its circular orbit is 2.2 x 10-3ms-1.Calculations show that the the gravitational force of the proton on the electron is 3.6 x 10-47N and the centripetal force on the electron revolving in its orbit is 8.32 x...

Hey,I have a question that reads:An electron of energy 10eV colliding with a hydrogen atom in it's ground state (-13.6eV) could have an energy of 0.2eV after the collision. True or False? (first excitation state -3.4eV)My teacher worked it out as true because the difference in energy levels is...

Suppose, we have have 2 masses having the following GIVEN properties. Each mass attracts another one with the force F=m1m2/r^2 (Newton's gravity law).Q: When do these 2 masses form BOUND system (let's call it "gravitational atom"), and when DON'T they form bound system?By other words, WHAT...

Is it possible at this stage in our state of knowledge to have an intuitive mental image of the atom?I suppose it wouldnt make sense to think of it visually because for starters electrons are a wave / probability distribution.Wht about protons and neutrons? Is it possible to visualise them?

The atoms this revolving compactions to substances named vacuum. About characteristic of this substances I wrote. The rotation creates the inertia (the mass). The revolvinging object has a virtual centre of the mass. His name is "the nucleus of the atom". Consequently nucleus of the atom this...

It is quite fasionable now talk about nanorobots and how smart they will be.I wonder, how "smart" can be a nanorobot consisting of 1 atom only?10 atoms?1000 atoms?

At the nuclear level of an atom, the CHARGE be it positive or negative is made up of what? what does it consist of?

Another good example of math shaping universe is such object as atom.Where does an atom (and its shape) come from?Suppose you have an electron and a proton with given properties (charge, spin, etc) - which are known. They (e and p) are passing by each other. Why don't electron just falls on a...

Maybe somebody can tell me if the concept I have of a hydrogen atom is consistent with what is being taught:The position where the proton is most likely located is the same as the most likely position of the electron. But since the electron has a smaller mass it would have a higher velocity if...

Poll Question:Four possible transitions for a hydrogen atom are as follows:(A) ni = 3; nf = 6 (B) ni = 5; nf = 3(C) ni = 8; nf = 4 (D) ni = 4 ; nf = 7(a) Which transition emits the shortest wavelength photon?Choices: b d c a

To make hydrogen stable without the electron falling toward the proton their has to be a force to prevent it.negative electromangetic field to be exact.the proton has a north and a south magnetic pole,it just can't produce a negative field by itself.so,when a electron comes close to a proton,the...

Could there be a particle small enough for light to pass through? Before you conclude and say yes, consider the compound light microscope I'm aiming somewhere else.Consider selective permeability in the cell membrane. The cell membrane could be light and the molecules it lets in could be this...

Having read relativity and QM I still havn't grasped the idea of how things would look if we could travel at light speed. When we look at the laws of relativity it seems very clear to me that matter which is subject to dementions and the laws which govern those dimentions can never be compared...

The philosopher Bas C. van Fraassen seems to state that only what we sense directly - without an intervening measuring device - is real. So the indirectly observed atom or amoeba is only theoretical, whereas the directly observed ant or Moon is real. The images of the former two, as seen...