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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What produces this 477 keV spectral line?

Question about a specific line on a gamma spectrum, here. Below is a background gamma spectrum observed by a Ge[li] detector. I've been able to identify all the lines with mostly certainty, apart ...
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1answer
24 views

What does the g mean after the isotope given?

I'm familiar with notation such as Sc-44m standing for the meta stable state of Sc-44. What does Sc-44g mean? There are a few examples of this notation; here's one: ...
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0answers
16 views

Gadolinium poisoning vs Holmium Poisoning [on hold]

Question here on the poisoning used around neutron spallation sources (or reactors, or any neutron source). I use poisoning in the sense of absorbing neutrons to prevent their release into the outside ...
2
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1answer
21 views

Gamma spectrum: Question about cross sections

If I have a gamma spectrum and I suspect that I should have an isotope, Fe-59 for example, present in the environment, I will then look here: ...
0
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0answers
21 views

Atomic/nuclear physics question

I've got what's probably quite a basic question here but I can't get things clear in my head. If I have a cobalt isotope like Co-56, is it possible for this to undergo Neutron capture (becoming ...
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3answers
335 views

Fission of U-235 produces Cs-137 along with…?

Question about Nuclear fission in general, here. If I have the fission of U-235 and I know that one of the products is Cs-137, is there a way of figuring out the other product? Should there be ...
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2answers
32 views

Slit width in single-slit diffraction

In Born's Atomic physics, he makes the comment on the single slit diffraction that For diffraction patterns to show themselves, it is necessary that the width of the slit employed should be of ...
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1answer
44 views

what make orbitals and can they be destroyed? [closed]

What is making an orbital to be an orbital? I mean how are the orbital formed. If big bang theory is true that there was nothing before the big bang then definitely these orbitals in the atom would ...
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28 views

Can steel rods be welded using “cold”?

Can steel rods be welded together by lowering the temperature to a point where each end becomes a BEC?
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1answer
45 views

Why is there no $1S_{-1/2} $ state of the hydrogen atom?

Heyho, i found this term scheme for the hydrogen atom: https://upload.wikimedia.org/wikipedia/commons/9/94/Wasserstoff_Aufspaltung.svg I was wondering why there is only a $1S_\frac{1}{2}$ state and ...
2
votes
1answer
20 views

Should I observe single/double escape peaks for all energies above 1022 keV

I have already asked a question similar to this, but that question was specifically relating to the case of K-40. I'm going to generalize it to any case My question is to do with the field of gamma ...
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2answers
55 views

Bohr Model of the Hydrogen Atom - Energy Levels of the Hydrogen Atom

Q.1) What is the idea of stationary orbital of electron? As it is said energy tangled with mass and vice versa how is this energy always be in the form of cloud such as s, p, d, f? From where does ...
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1answer
26 views

Nuclear decay of V-48

I have a question on the "decay" of Vanadium-48. The reason it's in inverted commas is because I'm not sure whether decay is the right word. Basically what I'm trying to work out is whether it's ...
3
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1answer
54 views

Why was the Stark effect discovered much later than the Zeeman effect?

This is strange. The Zeeman effect involves the magnetic field. The Stark effect involves the electric field. In the course of classical electrodynamics, we get the impression that for many physical ...
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2answers
45 views

How gamma rays are produced? [closed]

Radio active materials emit alpha beta and gamma rays. My question is, what causes (at subatomic level) an atom to produce such a powerful gamma rays and Suppose if I bring a fluorescent bulbs nearby ...
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2answers
142 views

Why don't electrons collide among themselves

The Heisenberg principle states that we cannot ascertain simultaneously the position or momentum of any small particle. However slight, is there a chance that 2 or more electrons from the same or ...
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2answers
846 views

Is there experimental verification of the s, p, d, f orbital shapes?

Have there been any experiments performed (or proposed) to prove that the shapes of the s,p,d,f orbitals correspond to our spatial reality as opposed to just being a figment of the mathematics that ...
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0answers
16 views

Transparency of atoms [duplicate]

Which is the specificity of the atoms which allow to pass the light, from which mass, from which composition of the core or the number of atoms the transparency falls. Electrons can collide with the ...
4
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0answers
59 views

Is it degeneracy pressure rather than electrostatic repulsion that stops us falling through the floor? [duplicate]

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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2answers
44 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
26 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 ...
5
votes
3answers
140 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 ...
2
votes
1answer
25 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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2answers
76 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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vote
1answer
247 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
41 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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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
34 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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25 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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3answers
72 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
25 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 ...
4
votes
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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0answers
18 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 ...
2
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1answer
24 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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26 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 ...
2
votes
4answers
161 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 ...
0
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1answer
62 views

Why do electrons occupy in discrete energy states?

Why can't there be any continuous energy band in an atom?
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7answers
341 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 ...
3
votes
2answers
68 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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0answers
20 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
votes
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 ...
2
votes
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 ...
3
votes
2answers
187 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 ...
36
votes
3answers
7k 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 ...
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0answers
52 views

Electron energy in magnetic field

For a problem early in a book I'm reading (Quantum Mechanics by Albert Messiah), I'm asked the following: Consider an electron following a circular trajectory in a constant magnetic field $H$ (I'm ...
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votes
0answers
28 views

Oscillation - atoms [closed]

A homogeneous, spherical electron cloud describes an atom (radius $a_0$ and total charge $^-e$ and positive point charge $^+e$ as the nucleus. An external electric field stimulates the electron ...
0
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1answer
47 views

Theoretical proof of the Bohr's postulates

It was proved in an experimental way that the energy of a photon equals $E = h \nu$ electrons radii satisfy the equation $mvr = n \hbar$ Is it possible to prove these properties in a theoretical ...
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3answers
79 views

Two questions about Variational Method of quantum mechanics

I have two question about variational method of quantum mechanics. Why we always find the ground state energy by this approach. Why not the other excited states? When we find the ground state energy ...