The property of some materials by which individual atoms decay, emitting energy or particles often transforming into different elements in the process.

learn more… | top users | synonyms

0
votes
0answers
17 views

Proportion of gamma rays in radioactivity from spent nuclear fuel [on hold]

In a Pressurised Water Reactor, a certain amount of radioactive waste is produced. Over a period of many years, often decades, it decays to give off alpha, beta and gamma rays. What proportion of this ...
-2
votes
1answer
54 views

How can alpha or beta emission maintain equal numbers of protons and electrons? [duplicate]

In radioactivity we know that a parent nucleus can disintegrate into daughter nuclei by emitting alpha or beta particles. If this is true then how can the daughter nucleus have as many electrons as ...
-1
votes
2answers
77 views

Left radioactivity in Hiroshima and Nagasaki [closed]

What is the level of the left radioactivity in Hiroshima and Nagasaki? It seems that people there live very well. So, the radioactivity is very low?
1
vote
2answers
46 views

Half life and Radioactive Decay

[Sorry about the misleading title, as the query isn't entirely about half-life, but I couldn't find any better way to condense my question to make a brief enough title anyways..... and] Radioactive ...
1
vote
1answer
30 views

Is anisotropic radioactivity really impossible?

What if the nucleus has a magnetic moment, and also the electron shell has one? I suspect, in this case, the orientation of the nucleus could be "fixed" by the electron shell. Maybe a mono-crystal of ...
1
vote
3answers
42 views

Growth and Decay, Law or not?

The differential equation for decay that applies to radioactive decay is: $$dN/dt=-kN$$ for a positive constant k and number of particles N. My question is: is this, strictly speaking, a "Law"? I ...
-1
votes
1answer
82 views

Are all radioisotopes equally dangerous? [closed]

I'm currently writing an issues investigation on the radioisotope plutonium-239. It's difficult to talk about the dangers of the radioisotope itself, since information on the internet is mixed. ...
3
votes
1answer
39 views

Why does a CfBe neutron source not exist?

Sources such as AmBe take advantage of Beryllium's $(\alpha,n)$ process to produce high energy neutrons. Sources such as Cf utilize spontaneous fission. Why not combine the two? Such a source would ...
1
vote
1answer
115 views

Who determined the half-life of Uranium 235 and how?

By Wiki, the half-life of Uranium 235 is as long as 703,800,000 years. This is huge. Therefore, on an human time scale, the decay is very small. This should pose difficulty for determining the half-...
7
votes
2answers
107 views

How can quantum tunnelling lead to spontaneous decay?

I have never understood what measuring process (if any) is supposed to be continuously polling the quantum state of an unstable bound system subjected to decay via quantum tunnelling. The reason I ...
1
vote
1answer
42 views

Cause of radioactivity

If Uranium-238 is hit by a neutron, it splits into different parts. My question is (a) Why throwing a neutron will destroy the equilibrium? Rather, should it not help maintain it? (As neutron is ...
3
votes
1answer
88 views

Measuring very long half lives accurately

There are already some questions about long half life times for radioactive elements, explaining how to calculate the half life time. Now I am wondering: When you have some radioactive material and ...
0
votes
1answer
20 views

Why is beta-minus decay considered isobaric?

Page 20 of Physics in Nuclear Medicine says that beta-minus decay is isobaric (eg the A/Z ratio remains the same). The reason it gives is that "mass number A does not change." However, in beta-minus ...
1
vote
1answer
48 views

Why do we use Bequerel to measure Radioactivity in food? [closed]

Wouldn't it be better to use the equivalent dose?
5
votes
2answers
315 views

Beta decay: is it OK that the products are not electrically neutral?

I'm just learning about radioactivity, and there's one thing I'm unclear about. Take $\beta -$ decay, for example. Since a neutron splits into a proton and an electron (and an anti neutrino), but ...
0
votes
2answers
63 views

Radioactive decay-Why does it depend on numbers left

As textbooks describe the rate law for radioactive decay as a first order reaction dN/dt=kN,why is it so(mine does not give the reason)? How is the radioactive decay of one atom depeendent on the ...
0
votes
0answers
18 views

Protonic emissions

In a beta emission a neutron decays,into a proton and an electron, and an electron randomly gets ejected from the nucleus due to the phenomenon of barrier tunnelling(correct me if am wrong).But why is ...
43
votes
3answers
7k views

Can radioactivity be slowed through time dilation?

Can radioactivity be slowed using the effect of time dilation? If you put cesium, tritium or uranium in a cyclotron at relativisitic speeds, do their half lives become longer in our frame? Could ...
1
vote
2answers
65 views

Question about calculating age of a uranium and lead containing object, based on the ratio of uranium-to-lead

I realize this is probably going to sound so stupid, but... here goes: Radioactive decay: We know that we can calculate the age of a uranium containing object by the uranium-to-lead ratio, due to ...
0
votes
1answer
14 views

Why does natural counting with a gamma spectrometer differ from Neutron activation analysis?

As stated in the title, why are the data from natural counting using s gamma spectrometer different than the data from neutron activation analysis using the same samples?
0
votes
2answers
42 views

Can electron capture occur with an external electron?

Can electron capture proceed with an electron not bound to the nucleus which decays (that is one that is bound to a neighboring atom, bound in a collective state like a conduction band, or free)?
2
votes
1answer
97 views

Radioactive decay of Uranium 238

Problem We have a cubic room of side $10$ m, into which no fresh air has been allowed to flow for a week. We register a specific activity of radon ($Rn-222$) of $50$ Bqm$^{-3}$. Knowing that $Rn-222$ ...
1
vote
0answers
34 views

Sustained nuclear criticality in liquid vortex

In 1958, chemical operator Cecil Kelley was killed by a nuclear excursion in a mixing tank. A tank intended to reprocess trace amounts of dissolved plutonium-239 accidentally had dramatically more ...
1
vote
2answers
98 views

Safety of Polonium Isotope source

I saw a YouTube video by a guy demonstrating Geiger Counter use and one of his radioactive test sources was a disk with Polonium. He casually mentioned that this was the poison used to kill that ...
3
votes
0answers
27 views

Detection of radioactive iodine at trash dumps [closed]

I have a cat that is getting radioactive iodine therapy and I am told I must flush the litter for 2 weeks because if I throw it away normally the dump will detect the radiation and fine me. This ...
1
vote
1answer
108 views

Long distance radiation detection, David Hahn and the clock

The strange character David Hahn, obsessed with creating a nuclear reactor since a young age, was reportedly wandering around his neighborhood with a Geiger counter and by this means he located a ...
0
votes
0answers
26 views

Why is nuclear waste, waste? [duplicate]

My colleagues and I are chatting and none of us know why nuclear waste is waste. That is to say, if something is still radioactive, why can't that radiation be used? Can't the energy from, at least ...
0
votes
3answers
68 views

Are Geiger counters isotope-specific?

I was talking with an employee at a company that does I-131 therapy for hyperthyroidism and they said that the Geiger counters they use are "tuned" for I-131, implying that regular Geiger counters are ...
0
votes
2answers
155 views

Calculate the probability that a radioactive nucleus will have decayed after the passage of three half-lives

This is a problem given in my Physics Textbook and I've been trying to solve it for the past hour. It's not something exceptionally challenging, but more conceptual in nature. Not much, connections ...
1
vote
2answers
44 views

What happens to covalent bonds after the nuclear transmutation of an atom in a molecule?

What happens when we have a decaying atom in a molecule, which has covalent bonds with other atoms? I assume some of the bonds will cease to exists, but I did not manage to find any rule about which ...
3
votes
2answers
59 views

Beta decay of radiocarbon

I read some weird equation on wikipedia about the beta decay of radiocarbon: ${^{14}_{6}C} \rightarrow {^{14}_{7}N} + e^{-} + \overline{\nu_{e}}$ The problem with this equation that it does not ...
8
votes
2answers
709 views

Can a half life be given in electron volts?

I'm using this link to search for particular energies in which gammas may be emitted (for nuclide identification on a gamma spectrum). If on the above link you go down to the "γ condition #1" line, ...
3
votes
2answers
274 views

Does hotter radioactive substance have longer half life?

Sorry to have a newbie question! But I want to ask, if it is possible to change the half life of radioactive substance by heating it, my hypothesis is: When substance becomes hotter, the kinetic ...
1
vote
1answer
42 views

Can alpha, beta or gamma radiations emitted by a radioactive substance be controlled? [duplicate]

Just saw this question in a school class 10 exam. Google search did not yield useful results. Can anyone please explain the answer here?
1
vote
0answers
32 views

Confusion about radioactivity

The following question is from General Problems on Physics by I.E Irodov 6.220. Find the decay constant and the mean lifetime of $^{55}\operatorname{Co}$ radionuclide if its activity is known to ...
0
votes
0answers
35 views

Peak in continous energy spectrum

I was reading online about particle decay. For the decay of Strontium-90 to Yttrium-90, a beta particle is emitted. The energy distribution of beta particle is continuous. If I know that the maximum ...
1
vote
3answers
30 views

Measuring Activity

The formula for Activity of a radioactive substance is $ \frac{dN}{dt}=A=λN $. If we have an initial number $N(0)$ of some Radionuclide, which has a halflife of, say, 12 hours, is there any ...
1
vote
0answers
37 views

Question on decay constant

I have a model of the radioactivity of a target which is undergoing Neutron Spallation. The Protons are incident upon the target for approximately 200 hours. Within the model, over the course of ...
1
vote
1answer
71 views

Is (or why isn't) static charge as lethal as ionizing radiation?

Ionizing radiation, e.g. the "stuff" emitted by radioactive materials, is dangerous to humans since changes to the electron configurations (in the human body) causes the various molecules (in the ...
1
vote
1answer
57 views

Predict decay chain of a radioactive element

I know there are tables of decay chain of radioactive elements. Is there a way to predict the whole chain from the first radioactive element?
11
votes
3answers
1k views

Why not dilute radioactive waste?

Radioactive wastes are dangerous because unstable elements are too concentrated. Originally radioactive elements come from nature where they were very diluted and that's why they were secure. So why ...
1
vote
1answer
96 views

Can the same isotope sometimes emit gamma rays alongside alpha (or beta) rays and sometimes emit just the alpha (or beta) rays?

Is it possible that sometimes all the energy goes to the alpha (or beta) particle so that no gamma rays are emitted and other times part of the energy is emitted as a gamma quant?
1
vote
2answers
165 views

How can I calculate the uncertainty in radioactive decay

So I have an exercise that says that the initial rate of $14\mathrm{C}$ was $13.5$ (per second) and nowadays it $10.8$ (per second). The half-life time is $5730$ years with an uncertainty of $30$ ...
1
vote
1answer
85 views

Error in total counts

I'm performing a radioactivity experiment where I measure a specific number of counts in some time period t. Later on I take the total count rate. (Number of counts/time: $N/t$) I'm supposed to find ...
0
votes
0answers
62 views

Electronic energy level in alpha and beta radioactivity

My textbook says that : " When a nucleus in an atom undergoes a radioactive decay, the electronic energy levels of the atom changes for alpha and beta radioactovity but not for gamma radioactovity. " ...
0
votes
1answer
40 views

Order of emission of radioactive particles

Is there any sort of sequence in the emission of radioactive particles? ie. alpha, beta, gamma or any other type of decay I don't know about. Specifically, I wanted to know is there any evidence to ...
-3
votes
1answer
104 views

Can a sample of beta radiation be considered as the fabled philosophers stone? [closed]

Given that it is possible to produce gold in nuclear reactors (even if not economical), is there a natural source of beta radiation whose half life is similar to that of human lifetime and whose beta ...
0
votes
2answers
66 views

why is gamma ray ejected during radioactive decay?

Why are gamma rays are emmited? Why is it not that an x ray or infrared or ultraviolet or cosmic or microwave ray is emmited?
2
votes
1answer
32 views

Effect of radioactive decay on the structure

In case of electricity, the understanding is that conductivity occurs only on the surface of the element.Is it true for radio-active decay as well ? If not and the decay occurs within the element, ...
1
vote
1answer
34 views

Notation on chart of the isotopes

I recently purchased a complete chart of the isotopes, (this one: https://shop.marktdienste.de/shoppages/produktuebersicht.aspx ) and have it on the wall next to me in work. The different coloured ...