Questions tagged [radioactivity]
The property of some materials by which individual atoms decay, emitting energy or particles often transforming into different elements in the process.
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Is crossing symmetry violated in the difference between positron emission and electron capture?
As discussed in the relevant Wikipedia article, beta decay via electron capture is possible in circumstances when positron emission is not.
From a simple (and perhaps naive) point of view, the two ...
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Is the rate of radioactive decay inversely proportional to the stability of an isotope?
Is the rate of radioactive decay inversely proportional to stability of the isotope?
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How to explain different, seemingly inconsistent, values for the mass of the alpha particle in different books?
I’m trying to calculate the energy of an $\alpha$ particle after the decay of Ra-226 following an example in a german school book and came across different values for the mass of an $\alpha$ particle.
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Radioactive decay : question [closed]
yo for this question, I'm unsure how to approach. We cannot just say that in 1200 years, x has 3 half lives and its daughter y has 4 half lives, therefore x is double y. This approach assumes that the ...
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Nuclear binding energy and natural radioactive decay
I have just started to learn about nuclear binding energy. While I believe I understand the concept well, there is one thing I do not still fully grasp.
I understand that the nuclear binding energy ...
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Why does Americium-241 not exist naturally?
A few searches says that it's because "the half life is too short with respect to the age of the universe." I don't understand what that means.
Note that the half life of Americium-241 is ...
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Having problems to find an equation for radioisotope production yield
I'm trying to find the required target mass for a specific nuclear reaction with a fixed yield and cross-section.
I am trying to get a plot, or a result for target like this:
I've found some ...
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How does the intensity of radioactive decay vary with distance?
I have a Sr-90 source which undergoes beta-decay. I measure the number of counts (n) detected by the detector as I increase the distance between source and detector. I then plot a graph of d vs (n/Δt)...
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Significance of continuity of normal vs. Poisson distribution in central limit theorem
Say I have an experiment where we have a radioactive source, and we measure the particles detected. At the start, we use a thin metal sheet to cover the detector such that the mean number of counts ...
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What happens to the velocity of a radioactively decaying object?
Suppose that I have a lump of a radioactive material, like Uranium-235. I put it in an ideal box, which perfectly isolates the inside from the outside - no radiation escapes the box and the outer ...
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Why is Astatine-210 (At-210) the longest-lived isotope of astatine despite possessing an odd number of neutrons?
I am guessing that isotopes with an even number of neutrons more readily release an alpha particle... When and if At-210 does that, it still has the problem of being 'odd/odd'...
But this begs the ...
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What determines the path in radioactive decay series?
How an element decays can be plotted in a diagram like this:
source: https://chem.libretexts.org/Courses/City_College_of_San_Francisco/Chemistry_101B/10%3A_Nuclear_Chemistry/10.3%3A_Radioactive_Decay
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How can imparted energy be a stochastic quantity?
It may be a silly question, but I have a dosimetry course and it started by defining deposed energy and imparted energy and for both it says that they're stochastic quantities. The mathematical ...
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Isotopes half-lives distribution - is it log-uniform?
Decay of single isotope follows exponential law.
BUT decay of nuke fallout / spent nuclear fuel will follow hyperbolic law. It is easy to explain if we assume that half-lives are log-uniformly ...
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How do we know photons are stable?
For something to decay time must have passed for that object. If I were to grab a block of super unstable material and look at $t=0$ none of it would have decayed. Now Einstein posits that time moves ...
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Relationship between reactivity and half lives
I understand that after the 4th half life, there will be $\frac{1}{16} = 0.0625$ of the original substance left but I'm not sure how to find the half life according to this graph (since it's not ...
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Why is Polonium so unstable compared to Bismuth?
Why is Polonium so much more radioactive than Bismuth? I've been wondering this for a while, and have searched around for an answer, but I can't seem to find anything that gives a good answer.
Bismuth-...
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What was the radiation dose of the witnesses of the Chicago Pile 1 experiment?
In descriptions of the Chicago Pile 1 experiment, where a self-sustaining chain reaction was first produced, scientists are standing directly around the pile. Some of them are even taking measurements ...
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How to calculate radioactivity concentration of components in reactor?
I understand the reactor parts will become radioactivity because there are neutron flux in reactor. How should we calculate the reactivity of reactor parts? For example lets say there is a reactor ...
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Do $\beta^+$ particles convert in an equal amount of $\gamma$ particles?
When $\beta ^+$ particles are stopped in alluminium they produce $\gamma$ radiation. My question is: is the amount of $\gamma$ radiation (whit alluminium infront of the counter) seen on a geiger ...
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Radioactive decay problem [closed]
Hey could someone please explain why the answer is C. I thought if the answer is C, the atomic number would be 44, not 50. I'm not sure I'm approaching this correctly. Thanks for any advice.
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What is the size of the beryllium in the Demon Core?
The Demon Core is covered by a hemisphere of beryllium. The Demon Core reaches criticality when the beryllium is completely closed. To achieve this, the size of the beryllium must be adjusted so that ...
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Why do things decay in terms of base $e$?
For instance, why do radioactive elements follow some $e^{-x}$ relationship? Why not $\pi^{-y}$ or some other numerical constant as the base? Is there some fundamental reason for Euler's number ...
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How does absorbing a free thermal neutron convert nitrogen-14 into carbon-14? (Radiocarbon dating, etc.)
Why doesn't a nuclide of N-14 simply absorb the neutron created by cosmic rays or solar wind interacting with the atmosphere and become N-15, which is stable?
How or why does the resulting Nitrogen-15 ...
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Infinity potential well [closed]
For infinity potential well we take the analogy with nucleus. Inside which proton and neutron are bound in principle, if it is an infinite potential well, so particle should not come outside the ...
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How do radioactive materials behave under extreme conditions?
Radioactive decay releases alpha particles like Helium. But helium also has extreme states at cold & high pressures.
So if the conditions for the extreme states like 1GPa-525GPa & 1-20K are ...
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Does the term "radiation" broadly include 'radioactive particles'?
In the current context of the Ukranian situation, but also in past contexts like the Fukushima incident, the press warns that "radiation may spread into distant areas..." and so on.
As I ...
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How to approximate the activity of radioactive product in chain decay?
I am trying to understand how do I get approximation for the activity for a radioactive nuclide that produced during a chain while the activity of the source is given at time $t_0$.
For example lets ...
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Number of photons per unit time produced from Cherenkov radiation
I am trying to create cherenkov radiation with radioactive source, I understand how to calculate the number of photons per unit lengh per unit wavelengh produced in a cherenkov radiation using the ...
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Does Radon Gas Worsen The Effectiveness or Usability of Consumer Grade Wireless Electronics? [closed]
Some notes:
I don't have a Geiger counter.
The wireless headset is near my computer.
It goes in and out of the audio signal.
The audio has audible cracks that sound like a Geiger counter.
My family ...
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Why we have not observed one proton and one neutron nuclear decay? [duplicate]
I'm learning about nuclear decays:
Alpha (helium nucleus, +2)
Beta (electron)
Gamma (photon)
Neutron
But why helium nucleus? Why not hydrogen nucleus (deuterium)?
I mean why two protons and two ...
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How does Radioactive Decay work under Special Relativity?
The other day I had the following thought experiment:
Envision that you have 1 kilogram of radioactive Promethium, which has a half-life of 17.3 years, which you put inside a box and load onto a ...
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Producing cherenkov radiation using radioactive source
I want to produce cherenkov radiation by transpering $\beta$ particles through a dialectric media. To do this , I will use a radioactive decay as a source for the $\beta$ particles, The thing that ...
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Experimental results for the measurement of Positron lifetime / Positron decay [duplicate]
It is assumed that the positron, being the antimatter particle of the electron, is stable.
I am interested in finding experimental results or experiments which have measured the positron lifetime in a ...
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Why is radioactive half-life constant?
Say you have just four radioactive atoms with a half-life of one hour. (I am using a small number of atoms to keep it simple and illustrate my confusion more clearly). So that means one hour from now, ...
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Difference between $e^-$ capture and $ β^+ $ decay
A nucleus stability is judged by it's n/p ratio, which it prefers to be ~1. If n/p ratio is much less than 1, an atom tries to increase neutrons and decrease protons present in the nucleus. My physics ...
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What if there are three less neutrons in $_{89}^{238}U$? [closed]
I am wondering what will happen if there are three less neutrons in $_{89}^{238}U$? I found this problem in a book. Will it produce $_{89}^{235}U$ or $_{92}^{235}U$?
The reason for choosing $_{92}^{...
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What is the half-life of isotopes that decay via electron capture, if they are stripped of their electrons?
If an isotope that undergoes decay via electron capture, like 7Be, loses ONE electron, how will its radioactive half life change? What about 2 electrons? And so on and so forth for heavier elements? ...
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Is it possible that enriched iron can "lose" it's enrichness?
I am doing Mössbauer spectroscopy at room temperature while using my source as a $^{57}$Co and using as my absorber enriched iron. The result I got for some reason is much more similar to iron than ...
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How can negative beta-decay energy be negative?
The International Atomic Energy Authority (IAEA)'s Nuclear Data Services list tables of nuclear data, including a table of atomic masses and beta decay energies, data taken from Huang et al., Chin ...
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Subtracting background from a radioactive measurement
To measure the activity of a certain sample, we need to also measure and subtract the background. An experiment I attended had explicit instructions that the background should be measured before AND ...
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Will a radioactive ball conserve its angular velocity?
Consider a uniform spinning sphere in vacuum. In principle it should spin forever, because of angular momentum conservation. However, assume that the sphere is made of radioactive material: since it ...
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What are some household sources of radiation detectable with a geiger counter?
I recently started rock tumbling with my preschool-age kids and bought a cheap geiger counter to check out rocks we find (more from curiosity than concern). Specifically it's a GQ GMC-500Plus model ...
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Variation of gamma line broadening with time of the source
What explains the broadening of the gamma linewidth as the source "gets old"?
I have been using Iron-57 in my radiation studies but the source I obtained 6 months ago shows significant line ...
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Energy as a function of half-life?
How much energy is released in the radioactive substance's decay of one cycle of its half life? I'd like the plot the energy released of a radioactive substance over time. What must I reference to ...
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How can a proton in a nucleus decay into neutron and positron in β+ decay if neutrons have greater mass than a proton? [duplicate]
I'm guessing it has something to do with mass defect/binding energy??
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How much faster does induced fission in a typical reactor occur than spontaneous fission in nature?
I know that the half-life of Uranium-235 is about 704 million years, but...
That includes alpha and beta radiation as well as spontaneous fission, though...
Also, I presume the 'spontaneous fission' ...
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Does a part of the difference in mass-energy excite the nucleus to a higher energy state during beta decay?
According to this site: https://byjus.com/physics/radioactivity-gamma-decay/
Most of the time, gamma decay occurs after the radioactive nuclei have undergone an alpha or a beta decay. The alpha and ...
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Reasoning behind alpha , beta to be not occuring at same time for any element
Is it true that Alpha decay can occur after beta decay and that Alpha decay and beta decay cannot happen at same time ?
If yes is my reasoning correct :
For both decays to ...
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Q-value of beta decay in different forms
Related to this previous post of mine The Beta Decay equation proper balancing , is it true that Q-value of beta decay reaction can be written in any of these two ways ?
$Q $= ${m _{X}}(_{Z}^{A}\...
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