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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Is it degeneracy pressure rather electrostatic repulsion that stops us falling through the floor?

From Wikipedia: Degeneracy Pressure Freeman Dyson showed that the imperviousness of solid matter is due to quantum degeneracy pressure rather than electrostatic repulsion as had been previously ...
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17 views

The difference between $R(r)$ vs $r$ graph for $4s$ and $5p$ orbital

Both orbitals have equal number of radial nodes (number of radial nodes = $n-l-1=3$). So the curve cuts the $x$-axis in 3 points. If it was $\psi^2$ vs $r$, then the curve would touch the $x$-axis at ...
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2answers
38 views

If I touch an object, am I touching the atoms on its surface? [duplicate]

If I hit an object with a pen for example, does the pen touch the atoms on the surface of the object? Won't it damage the atoms? If I can't touch it, then where does the sound come from?
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1answer
275 views

Why is the orbital angular momentum of a pi electron along the axis of two atoms' molecule one?

I'm reading quantum chemistry. The book says that the orbital angular momentum of a $\pi$ electron along the symmetry axis of a molecule made up of two atoms is $\pm 1$. I think this is a primary ...
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17 views

Speed of Electron delta orbital function [on hold]

Is there a function that determines the delta in speed of electrons in subsequent orbitals? If so, is it the same for all elements or does it differ because of relativistic effects? Would an electron ...
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1answer
87 views

Atomic physics - lattice energy

Question: Why is ionic lattice energy inversely proportional to the radius of the atom? Most heterogeneous covalent molecules are polar to some extent. The degree of polarity, or the dipole moment, ...
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1answer
284 views

Wigner Threshold law in Photodetachment and Photoionization

I am writing this question here because I have a problem in understanding the Wigner Threshold law in Photodetachment and Photoionization. The Wigner Threshold Law is given by: $\sigma$=$E^{L+1/2}$. ...
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1answer
23 views

Accounting for the thermal excitation in the Richardson-Dushmann equation or the work function equation

When accounting for thermal excitation in a system that is not in thermal equilibrium, heat is constantly flowing through a material, should I account for the thermal excitation in the work function ...
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23 views

Effective mass in a Bohr atom [on hold]

I was solving a question in a hypothetical situation, in which a carbon atom consists of 6 pions instead of an electrons. Acoording to Bohr model of an atom, what would be the ground state energy of ...
2
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1answer
89 views

Is a Plutonium gun-type atomic bomb really “impossible”?

I caught a pretty well done 2 hour documentary on atomic bomb history yesterday on the local PBS station. In it, they go over the paths taken for design of the first bombs, including the Thin Man ...
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2answers
72 views

Would a piece of paper look as big as a small bedroom to an atom?, or bigger? [closed]

This evening my six year old asked me "Would a piece of paper look as big as this room to an atom?, or bigger?" ('this room' being a small sized bedroom) A friend suggested it would probably ...
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1answer
22 views

variation of electrostatic potential on moving radially outwards from the nucleus of an atom

I was wondering how would the electrostatic potential change on moving radially outwards from the nucleus in an atom, considering the effect of the electron clouds around it.
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1answer
142 views

What is the most accurate experimental confirmation of Rutherford's $\sin^{-4}\phi/2$ law?

What is the most accurate experimental confirmation to date of Rutherford's $\sin^{-4}\phi/2$ law, where $\phi$ is the scattering angle?
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1answer
97 views

How does exciting an electron's surrounding electromagnetic field cause 'electron excitation'?

In more meaningful words than the ones above, how does adding energy to the EM field cause the electron to to change orbitals or oscillate in a different pattern.
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1answer
234 views

Total orbital and spin angular momentum for a closed shell

I read one Phys.SE question similar to mine, in Total angular momentum in a full shell but the question was so confusing and vague. The answer, though, was helpful for me to understand a part of my ...
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2answers
39 views

Hydrogen Balmer Series

Hydrogen contains electron of n=1, Balmer Series requires electrons to jump from n=2 to n=3,4,5.... and again back to n=2. As n=2 is empty for Hydrogen atom, then how Balmer Series is formed for ...
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1answer
118 views

Thermionic emission, delayed emission and predissociation

In molecular photodissociation, the thermionic emission, delayed emission and predissociation are the same? Otherwise, what is the difference between them? My question is not about the solids, but I ...
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0answers
28 views

What are some of the failed experiments to determine electron's position? [closed]

One that I could think of is trying to observe it with the help of electromagnetic radiation which could tear apart the atom. I asked this because I want to know what sort of methods are used to ...
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1answer
28 views

When does electron capture occur and when does positron emission occur?

I’ve been told that electron capture occurs when there isn’t enough energy to produce a positron by beta plus decay. Exactly why is this the case? Why does it take more energy for positron emission ...
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41 views

Why do the quantum numbers take the value they do? [duplicate]

Clearly $n$ can take any positive integer value. But what is the physics and maths behind $l=0,1,...,n-1$ and $m_l=-l,-l+1,...,l-1,l$? i.e. where do these ranges of values come from? (P.S. I know ...
2
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3answers
331 views

What force creates ions out of neutral atoms?

Consider the reaction between Na and Cl to form NaCl. Na loses an electron and "gives" it to Cl because this makes both atoms more stable. But what forces "pulls" the electron from Na to Cl? Both ...
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3answers
60 views

Why does noble gas electron configuration have low energy?

In chemistry classes in primary school we learned that atoms "want" to reach noble gas configuration because it have low energy, so atoms on the left of the periodic table are willing to give away ...
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2answers
24 views

Excitation of paired electrons in electron orbitals

When we consider the electron orbitals each orbital can have a single electron or an electron pair each with opposite spin. Are all electrons always in pairs except the final single one if odd number ...
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24 views

How is it possible to combine various techniques in cold atom experiments?

I’ve been reading about laser-trapped cold atoms (6Li in particular, which is a fermion) and was amazed at the number of things to keep track of in the experiments, just to gain that degree of control ...
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1answer
135 views

Total magnetic moment in an atom

I have a doubt regarding the calculation of total angular momentum of electron in an atom. Which is the right way to do it? Method 1: Total magnetic moment $$ \begin{align} \vec{\mu_J} &= ...
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1answer
41 views

Can an electron in an atom have insufficient energy to achieve an energy level, or orbital, and what happens to this electron when this occurs?

If a nucleus undergoes a change in Z or Mass due decay or absorption, could this disrupt the electrons from their orbital/shell energy levels? If so, could the electrons that were previously in the ...
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2answers
118 views

Is fluorescence from a single atom/ion visible with the naked eye (e.g. in a strongly coupled trap or cavity)

I remember sitting in on a conference talk by a person (possibly Rainer Blatt) doing research with trapped ions (or single atoms strongly coupled to light in an optical cavity), and the person showed ...
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15 views

Effect of nucleus geometry and states on the Coulomb barrier and the electric potential well surrounding the nucleus

In some models of the nucleus it has a geometric aspect due to the combination and alignments of the charges, magnetic moments and spins of the protons and neutrons it contains. Even in models that ...
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17 views

Can a light element with excited nucleus undergo internal conversion

Internal conversion occurs when an excited nucleus ejects a low level electron from the first 2 low energy shells such as a k shell electron instead of emitting gamma when returning to ground state. ...
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20 views

Does the mass of a nucleus increase when it is excited to higher energy levels

If we consider an atomic nucleus that is excited to a higher energy level. This maybe due to absorption of gamma for example or as a result of some other decay or interaction. Would the mass of that ...
3
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2answers
60 views

Effect on electron shells energy levels during nuclear decay

First thanks for this great site. I was recently looking at photon emission from electron transitions from excited electron states in atoms. For simplicity I was using the Rutherford Bohr Model and ...
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1answer
59 views
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7answers
307 views

Quantization vs. continuous energy levels

I still don't get what it means for atomic energy levels to be continuous or quantitized (incontinuous). Clearing this up will really help me. Also, can anyone tell me why energy levels in solids are ...
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4answers
140 views

How to explain what an electron is to someone new to physics? [closed]

I've got asked by someone who just graduated school and is about to start studying physics, what exactly is an electron, if it is not "a small ball rotating around the core of an atom". I couldn't ...
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1answer
174 views

Size of hydrogenic atoms

Positronium consists of an electron and a positron. By what factor is a positronium atom bigger than a hydrogen atom? The solution has been explained to me. The characteristic length when solving ...
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15 views

Coupling schemes

If it is multi electron system LS or JJ coupling schemes are used to evaluate total angular momentum (J value). Now my doubt, whether we have to consider all electrons or electrons in the outermost ...
0
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1answer
85 views

Can electromagnetic fields be used to deconstruct and reconstruct molecular bonds?

I was thinking one day and came up with a theory after reading about how scientists were studying anti-matter by using electro magnetic fields to separate matter from the anti-matter they made. It got ...
2
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1answer
103 views

Algebraic solution of Dirac equation for Coulomb potential

The Runge-Lenz operator enables an algebraic solution of Coulomb potential energy levels without a solution of a differential equation. What is the analog for the solution of the Dirac equation in a ...
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2answers
178 views

Unknown magnetic moment of orthohydrogen

Conforming to present atomic physics, the two elementary particles in hydrogen atoms can have either parallel or antiparallel magnetic moments, and the energy differences between these two kinds of ...
3
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1answer
114 views

Observation of gauge in artificial magnetic fields

In the ultracold atom community, an "artificial gauge field" or "artificial magnetic field" is a spatially varying hopping phase somehow engineered into the system, so that atoms hopping around an ...
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1answer
24 views

How fast can a fluorescent lamp flicker

Using electronic ballasts, the current frequency is boosted up to 60 kHz in some models. Does the fluorescent lamp continue to flicker at that frequency or does it produce continuous light? In this ...
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5answers
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Why is the sky never green? It can be blue or orange, and green is in between!

I, like everybody I suppose, have read the explanations why the colour of the sky is blue: ... the two most common types of matter present in the atmosphere are gaseous nitrogen and oxygen. ...
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2answers
42 views

How are determined experimentally the energy levels of the atoms ? How is the calibration done to several decimal points?

I see discrepancy for the absorption edges for the atoms in the X-ray ? For example K-absorption edge of carbon can be anywhere between 282 to 284eV according to different sources. My question is ...
2
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0answers
35 views

Why Electron Does Not Radiate In Bohr Orbits? [duplicate]

Maxwell said that charged particles radiate when are in accelarating motion. I understand that $nλ=2πr$ must be fulfilled in order to create a sinusoidal standing wave and to satisfy the probability ...
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0answers
31 views

What does 'easily reversed' mean in the NIST spectral database? [closed]

Cross posted to http://engineering.stackexchange.com/q/3303/ I'm trying to do some processing of optical emission spectra from sputtering plasmas, and am confused by what NIST means by 'easily ...
36
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3answers
6k views

In atomic bomb tests under ground, where does the volume of the rocks go?

Underground atomic bomb tests are done in a deep, sealed hole. Not all underground tests eject material on the surface. In this case, they are only noticeable as earthquakes, according to german ...
3
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2answers
178 views

Quantum mechanics and the atom

I was thinking about the nature of the atom, specifically, why electrons do not spiral into the nucleus. My physics book says the principal quantum number $n$ must be an integer number of wave ...
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0answers
24 views

Is density of an element directly proportional to atomic number or atomic weight? [duplicate]

Is the density of an element directly proportional to any power/order of atomic weight or atomic number? I know very less, probably only highschool level physics, after which my brain has been ...
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2answers
289 views

Book recommendation for Atomic & Molecular physics

What are some interesting books for a sophomore undergrad about Atomic & Molecular Physics?
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1k views

An atomic bomb explodes inside of an “unbreakable” container which is on a scale. Does the “weight” of the container change?

I read that most of the "mass" in the proton was actually energy from the quarks and gluons, as opposed to the actual mass which was coupled to the Higgs field. This made me start thinking about ...