Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. It is primarily concerned with the arrangement of electrons around the nucleus and the processes by which these arrangements change. This includes ions as well as neutral atoms and, ...

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Charge on the remaining atom after Alpha decay

In radioactive alpha decay, a helium atom is shown to be released. However, I was told that only thing released is a helium nucleus. If so, then it should leave two of its electrons in the atom ...
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Magnetic quantum numbers - axes correspondence

We know that the magnetic quantum number describes the space orientation of an orbital within an atom. For the $p$-orbital, the magnetic quantum numbers can be -1,0,1 (one for every axis). We have ...
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Why are the quantum numbers $n$ and $\ell$ denoted with those letters?

We have 4 quantum numbers: principal, azimuthal, magnetic and spin (denoted $n$, $\ell$, $m$ and $s$ respectively). I assume $m$ and $s$ are simply the initials of 'magnetic' and 'spin'. Is there any ...
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107 views

Do electrons pop into and out of existence around the nucleus of an atom?

What surrounds the nucleus is the probability wave. But are the electrons constantly popping in and out of existence around the nucleus in the cloud?
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27 views

Gain of entropy

Can we really interpretate third thermodynamic law as unconditional gain of entropy of closed system? For example, when they separate U 235, they drive the mix on the pressure barrier, so heavier U ...
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71 views

Is it possible to single out a proton, electron, neutron?

I've read that it's nearly impossible to take a proton from an element. But if it's "nearly" impossible then it is possible to some degree. If this has happened, what is exactly the process of taking ...
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27 views

Dipole approximation in solids

I have seen the use of dipole approximation (where the extent of the wave function is assumed to be much smaller than the wavelengths of the transitions or that of the electromagnetic field applied) ...
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36 views

DFT Calculations, Atomic Ionization Potentials — Which Exchange-Correlation Functional to Use, to Preserve Koopmans' Theorem?

I have a program which can perform density-functional calculations for atoms, given a density functional. Of course the simplest form of exchange potential to use is one relevant for a uniform ...
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90 views

How do I calculate the most probable orbital an electron is in?

If I saw a snapshot in time of an electron near a proton (Hydrogen), then the electron can be in any orbital as long as it doesn't lie on a node of the wave function. So how would I determine which ...
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How to derive the electron dipole selection rule in coupled bases?

We need to find $| \psi_f \rangle$ fulfilling the condition that $$ | \langle \psi_f | \mathbf{x} | \psi_i \rangle |^2 \neq 0.$$ When using the uncoupled bases $| l,m,m_s \rangle$ I can derive the ...
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22 views

Should it really be called “valence *sub*shell”?

The Wikipedia article on electron shells states this, which I (a chemical layman) also always assumed: The electrons in the outermost occupied shell (or shells) determine the chemical properties ...
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What is the potential between two hydrogen atoms in the spin-triplet state?

Take the Born-Oppenheimer approximation. Assume the two electrons are in the spin-triplet state. How does the potential between two hydrogen atoms look like?
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535 views

Why do we use the Coulomb potential for the hydrogen atom?

When solving the Schrodinger equation for the hydrogen atom, the Coulomb potential $V = \frac{e^2}{4 \pi \epsilon_0 r}$ is used. The Coulomb potential comes from classical electrodynamics, so why ...
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91 views

How can we prove that the shape of atom is spherical? [closed]

i am looking for a derivation that can prove that the shape of an atom is spherical . I experimentally proved this statement but i need a theoretical way.
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604 views

Why is Graphene Transparent?

Graphene is always in the news now a days and its key features are that it is; very strong, conductive and transparent. It is so transparent that each layer of graphene will only absorb 2% of Light ...
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53 views

Why is Graphene So Strong?

There has been a lot of news about Graphene since its discovery in 2004. And as we are all told it is a revolutionary material which is very strong, conductive and transparent. But what is it about ...
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24 views

photon absorption and emission

I was reading a book (Sears Zemansky) about this subject but I didn't understand something of an example, and this is that according to me there should be a process of emission for each of absorption ...
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20 views

What's the elementary reason for the formation of a band gap?

Bohr's solution for an isolated hydrogen atom showed that there are only discrete allowed energy levels, $E_n = -{E_0\over n^2}$ and the solution of the Schreodinger equation provided a certain ...
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20 views

How does An Electric Field Create a Dipole Moment of a Rydberg Atom?

I know that an Rydberg Atom will not usually have a Dipole Moment - as the positive nucleus are surrounded by a negative electron cloud, so there is no uneven charge distribution. However, I also ...
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25 views

Why Do Stark Manifold Graphs All Have Negative Energy?

I have been studying Rydberg-Stark State Atoms and their Stark Manifolds (like the one on Wikipedia: http://en.wikipedia.org/wiki/File:Hfspec1.jpg) and I was wondering, Why does the y-axis (of Energy ...
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51 views

How does a electron revolve in Rutherford's model? [duplicate]

How can an electron revolve in a circular orbit because circular motion is an accelerated motion and acc. charged particle is a source of E.M. Wave. So,it should radiate out energy and hence would ...
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43 views

Are there materials with more than two states that can be used in circuit design? [closed]

Are there atoms or materials that have 3 or more states that can be used in circuit design? Can you provide any examples of such materials, and their possible applications to circuit design? And is ...
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How did Rutherford's gold foil disprove the plum pudding model?

What stops one of the two following scenarios from happening, consistent with the plum pudding model? The $\alpha$ particle, attracted by the electrons on the outer shell of the pudding, orbits ...
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Does the mass of an electron change with its “energy state”?

When an electron absorbs a photon, it gets into a higher energy state and goes into the upper orbit/shell. Does (rather should) this absorption of energy also have an impact on its mass (although ...
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65 views

Electron gas in metals: more like a liquid?

I'm trying to form a figure in my head about how electron bindings look like in metals. The electrons in metals can move freely, as opposed to their pair-bindings in molecules, and form what is often ...
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54 views

Why anomalous Zeeman effect is more common? [closed]

Why anomalous Zeeman effect is more common? Gone through many books, searched on Google, but couldn't find the answer.
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53 views

Does electron in an $s$-orbital have angular momentum?

I've read on science forum that electron in orbital $s$ has no angular momentum and would fall into nucleus, so hydrogen atom would not be possible. Electron has mass and speed after all right? So how ...
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Are atoms made of protons, electrons and neutrinos?

If neutrons decay into proton, electron and (anti)neutrino of electron type, then is it safe to say that atoms are protons, electrons and neutrinos?
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Do atomic orbitals exist in a fully ionised atom?

Say a H atom is ionised and then it captures a free electron at a later time, do the atomic orbitals then have to go through a transitory phase to accommodate the electron before they form the correct ...
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76 views

Difference between a hydrogen ion and a proton

I've run into a bit of a problem on this weeks coursework. A proton and an electron initially at rest combine to form hydrogen. Find the wavelength of the emitted photon? So, as far as I can ...
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177 views

Why are neutrons present in an atom? [duplicate]

I have a very stupid question perhaps, but please answer me. An atom consists of electrons, protons, neutrons. protons are positively charged and electrons are equally negatively charged. The charge ...
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21 views

Photo-excitation in terms of particle physics [duplicate]

How does a photon couple to an electron during an excitation/de-excitation process in an atom? My current understanding is rather limited especially when considering types of fundamental forces and ...
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1answer
22 views

Is it more difficult to create higher energy photons, given there is excess available energy?

Im not talking about pair production, I mean a single photon created from an energy transition between two electron shells. I'm studying K(alpha) and K(beta) fluorescence transitions in metals, and ...
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48 views

Does an electron possess potential energy while revolving around a nucleus ?

Does an electron possess potential energy while revolving around a nucleus ? I guess that it wont. Why because when an energy is given it converts into its kinetic energy so that it revolves around ...
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20 views

Photon absorption by a hydrogen atom : [duplicate]

How does the photon absorption takes place in a hydrogen? The classical mechanics shows the absorption of photonic energy resulting in the excitation of atom. Intuitively, a photon with frequency ...
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54 views

Is there any physical simulator precise to atomic levels and quantum effects? [duplicate]

There are tons and tons of physics simulators for classical/large scale physics. I'm interested in a simulator in which you feed an input as atoms and positions and it simulates the evolution of the ...
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30 views

Can all energetic photon excite an electron?

Consider a hydrogen atom, to excite the electron to a higher orbit, it should interact with photons of energy equal to that of the energy difference between the two states. If the energy of photon is ...
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29 views

Derivation optical depth cloud of atoms

According to Wikipedia, "the optical depth $\tau$ of a cloud of atoms is given by $$ \tau = \frac{d^2 \nu N} {2 c \hbar \epsilon_0 A \gamma}, $$ where $d$ denotes the transition dipole moment, ...
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Property of $Cu$ so that it is used as target in in X-ray diffraction (XRD)?

Why only $Cu$ is used as target element in X-ray diffraction (XRD)? Why not other elements? And which rays has high intensity $k_\alpha$ or $k_\beta$?
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How large can an atom get? What's the farthest an electron can be from its nucleus?

For example, would it be possible to excite a hydrogen atom so that it's the size of a tennis ball? I'm thinking the electron would break free at some point, or it just gets practically harder to keep ...
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112 views

Centrifugal force in the Hydrogen atom for $L=0$

I have found the following interesting article: http://arxiv.org/abs/0706.0924 The authors examine the radial momentum operator in detail, in particular its time evolution due to the forces acting ...
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97 views

Do electrons “check in” at the quantized energy radius before they leap?

Quantum jumps inside atoms always have the same energy, at least in a hydrogen atom when jumping from $n=1$ to $n=2$, like from a 1s1 to a 2s1 state. My question is, if an electron can be anywhere in ...
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50 views

Choice of the z-axis in the Schrödinger equation for the hydrogen atom

I am reading about the solution of the Schrödinger equation for the hydrogen atom and have a question about the choice of the z-axis. Most websites say that the z-axis is arbitrarily chosen. If so, ...
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193 views

How big is an excited hydrogen atom?

Suppose an empty universe with the exception of a single hydrogen atom (1 proton, 1 electron). The electron may be in its ground state or it may be excited a certain number of levels. Suppose it is at ...
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39 views

Are we close enough to objects?

Are we able to touch the atomic orbital of an element ? If so, wouldn't there be a current flowing ? If not, then where do we actually touch when we hold it ?
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82 views

Picturing electrons

I used to think that the electron is a particle orbiting the nucleus, but now I know that the electron can be also thought of as a standing wave. That's kind of like saying that a curve is both ...
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106 views

Quantised Angular Momentum?

So when learning about the Bohr model of hydrogen and de Broglie waves, it was shown that treating the electron of hydrogen as a de Broglie wave results in the relationship $$L=n\hbar, \qquad ...
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64 views

Can we calculate L-S coupling without Dirac equation?

It is known that there exists an orbital and spin angular momentum coupling for an electron moving in the atom. And the Hamiltonian can be directly derived using Dirac equation. I want to use a ...
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How many atoms exist within a continuum body?

Materials, such as solids, liquids and gases, are composed of molecules separated by "empty" space. On a microscopic scale, materials have cracks and discontinuities. However, certain physical ...
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How would one detect antihydrogen in the universe?

Since the spectra of hydrogen and antihydrogen are the same, how do astronomers know which one they're detecting? Is, perhaps, the Lamb shift in antihydrogen different?