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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What thickness of lead sheeting would be required to block the following radiation hazards: gamma, cosmic, ion storm, any others...(cont.)>>> [closed]

What thickness of lead sheeting, would be required to block the following radiation hazards: gamma, cosmic, ion storm, any others. If all, or some of all, events via the sun [as further indicated by/...
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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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4 answers
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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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The Beta Decay equation proper balancing

The beta decay reaction is given by : ${ }_{Z}^{A} \mathrm{X} \rightarrow \underset{Z+1}{A} \mathrm{X}^{\prime}+\mathrm{e}^{-}+\overline{\nu}$. I would like to know the reason why cannot we write it ...
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If plutonium-238 (Pu-238) absorbs a neutron, does it become Pu-239?

I am asking this simple question because I am always hearing about how thorium reactors are less perilous to the world because, unlike uranium reactors, they produce some Pu-238, which is not suitable ...
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How exactly Radiocarbon dating Works?

So how exactly does Carbon Dating work ? $^{14}$C is produced from $^{14}$N in the atmosphere. Since there is considerable amount of Nitrogen in the atmosphere,we can have quantifiable amount of $^{14}...
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What determines the half-life (or stability) of an isotope?

Why is it that some elements do not have any stable isotopes, while others of very similar mass have multiple stable isotopes? What determines this phenomenon and what determines the strict ...
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Which is more: Energy released by nuclear fission or fusion? [closed]

The energy released by one fission reaction is 190MeV and the energy released by one fusion reaction is 24.7MeV. Then by my common sense 190>24.7 so energy released by fission>fusion but the ...
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Half-Life for Few Nuclei in a Sample

I read somewhere in some textbook that "The concept of half life and mean half life becom meaningless ehen you have a sample containing only a few nuclei. For example, if you are given say, 100 ...
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Why is the radioactive decay formula consistently overestimating number of non-decayed particles?

The radioactive decay formula is $$ N(t) = N_{0}e^{- \lambda t} $$ My understanding is that $\lambda$ indicates the probability of decay per unit time. Let's say $\lambda = 0.5 s^{-1}$. So we would ...
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Why mean life of radioactive element is slightly greater than halflife..? [duplicate]

I was reading radioactivity where I find that half life of a radioactive material is less than mean life due the presence of $\log2$ in the numerator: $$ t_{1/2} = \frac{0.693}{\lambda} $$ But how ...
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How photon beam can be attained through Proton Accelerator?

I'm recently had been reading quite a lot about ADS and transmutation possiblity of Proton beam to neutralize nuclear waste. I came across with an Article from Big THINK https://bigthink.com/the-...
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Can the variation of count rate over distance for a disk radioactive source be treated as an electric field of a disk charge problem

So I did an experiment in which the count rate of a disk source of Sr-90 is measured using a plane detector, varied from ~0.7cm to 100cm, multiplying the count rate by the distances squared (i.e. $\...
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How was Enrico Fermi able to predict a power output from his uranium and graphite Chicago Pile 1 (CP-1) reactor?

Uranium and graphite heat engine physics - early detection methods I've been inspired by the early developments in fission heat engines which happened even before uranium enrichment methods were ...
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Time constant versus half-life — when to use which?

In some systems we use half-life (like in radioactivity) which gives us time until a quantity changes by 50% — while in other instances (like in RC circuits) we use time constants. In both cases the ...
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Isotope that decays when ionized

Some time ago, I read about a certain isotope that is stable when neutral but decays with electron emission (beta) when being completely ionized, but I can't find which one it was. Which isotope ...
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Do samples of radioactive materials in vaccum, produce ions and acquire net charges

Suppose an atom decays via a $\beta^-$ decay, it's atomic number has increased by one, and an electron is emitted. $$ _Z^AX \quad \to \quad_{Z+1}^{\quad A}X'\ + \ _{-1}^{\ \ 0}e^- \ + \ \bar v _e $$ ...
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How do I determine the half-life from a change in the activity of a sample over a known time?

If I know that the sample originally has an activity of $A_0$ and after a time $t$ has an activity of $A_1$, how can I use this to determine the half-life of the material?
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Would it be possible to have a stable atom nucleus that is hollow?

Some context around my understanding: Protons and neutrons clump together in the core of the atom due to the strong nuclear force. Protons also repel each other, but the strength of this is not strong ...
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Radioactivity inside black hole

This is thought experiment. I know we can not insert or watch happening inside black hole. But for sake of thought experiment let's think this is possible. Suppose we have 1 kg of material X with half ...
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How might one stop a radioactive agent from radiating?

Source There have also been grim signs of things to come from the Russian government. A new national standard for “Urgent burial of corpses in peacetime and wartime” has been introduced by the ...
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Why does the product nucleus lose an electron during beta positive decay process?

The question describes the beta positive decay for Nitrogen-13 into Carbon-13. After reading the explanation for the answer, it says that carbon ion will lose an electron in the decay process; ...
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Question about third Newton's law applied to nuclear fission

My question is about the energy that is gained by fission of Uranium 235.Suppose we have a box opened on one side where the radiation is emitted...so if that side looks to the sky that box should be ...
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What is the *fundamental* reason, at particle level, of the radioactivity?

When giving fundamental reason for radioactivity, books or references most often state that this is due to the fact that nucleus is not in a stable enough state thus it goes back to the stability. ...
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Why $\beta^+$ radioactivity is possible while lifetime of proton is expected to be infinite?

In the Standard Model, protons are considered to have an infinite lifetime. See https://en.wikipedia.org/wiki/Proton#Stability "The spontaneous decay of free protons has never been observed, and ...
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Is Radon a gas due to its radioactivity?

I think most gases are light but Radon is really heavy. I of course know that plenty of gases are not radioactive, but could the reason that Radon is a gas be due to the radiation contributing to the ...
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Decay probability

If I have a nucleus that have a constant probability per unit time to decay $q$ (to simplify is the probability to decay per day), Me and my friend decided to make a bet: the nucleus is alive at the ...
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How nucleons get excited? [duplicate]

Gamma rays can be released when nucleons at higher energy states fall down to lower energy states, but how do nucleons get that much high energy to release gamma rays?
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How to model radiation from non point sources?

For radioactive decay, if we assume a point source, then the number of particles at a distance $d$ away from the source scales as $1 \ /$ $d^2$. The assumption of a point source is only valid when d ...
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