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.

Filter by
Sorted by
Tagged with
1
vote
2answers
35 views

What is an “excited nuclear isomer”?

I have been making an excel spreadsheet of all nuclides with half-lifes 20 hours or longer. If you look on the any of Wikipedia's "Isotopes of [insert any found element here]" pages, you ...
-1
votes
1answer
21 views

Storing large quantities of potassium salts: nuclear radiation [closed]

Assuming I store $300 \;\text{kg}$ of potassium hydroxide in plastic bags on a palette in my living room. This is equivalent to $5347 \;\text{mol}$ of potassium content or roughly $0.626 \;\text{mol}$ ...
0
votes
1answer
39 views

How to produce ionizing radiation without radioactive substance?

I think ionizing radiation caused by ray or particles. My professor told me:"without radioactive substance,with only commercial products,it's possible to produce ionizing radiation." Can ...
0
votes
0answers
20 views

Carbon Dating - Same age but different original radioactive nuclide left

2 same trees but diferent sizes fell 2000 years ago. We are trying to find their age using carbon dating. So my understanding is that their age will come to be same approx 2000 years but percentage of ...
2
votes
1answer
36 views

Probability in simultaneous parallel radioactive decay

Probability of survival (PoS) and probability of decay(PoD) in simple radioactive decay (X --> Y : $\lambda$ as disintegration constant) are given by: PoS = $e^{-\lambda t}$ and PoD = $ 1- e^{-\...
1
vote
1answer
54 views

Why free neutrons are usually produced in a Nuclear Fission?

The production of neutrons is a feature of fission reaction. Usually 2-3 free neutrons are produced in the fission. Why is that so?
0
votes
0answers
9 views

Excitation of nucleus in radioactive decay

When I say that a nucleus is unstable, does this mean that the nucleus is in its excited state?
1
vote
1answer
69 views

What factors affect the rate of decay of a radioactive atom? [duplicate]

I saw a specific quote that made me question this : "Other atoms in the universe don't influence the rate, it's just an intrinsic property of each separate atom that it has some chance to decay.&...
1
vote
0answers
13 views

How do I calculate the Sieverts/hour that a gamma meter would see at x distance from a radioactive sample?

I'm working on a little proof of concept program where I want to input some weight of a radioactive element, and then calculate what a meter would read at different distances. Ultimately I hope to ...
2
votes
2answers
66 views

Can muons be used to reach the island of stability of superheavy elements?

While reading about the island of stability of superheavy elements[0], experimental approaches and related difficulties[1], an idea has formed in my head. Since I cannot find considerations of such ...
0
votes
0answers
27 views

Radioactive decay and particle collisions

I've been reading some popular science books regarding particle physics where they mention how collisions of subatomic particles at high speeds can create new particles. Also radioactive decay creates ...
0
votes
0answers
25 views

Why aren't gamma rays more ionizing than beta and alpha rays considering the fact that it is the highest energy photon and very penetrative?

Gamma rays are photons and light waves that have more than enough energy to excite an electron and break its bond. So why aren't they more ionizing than beta and alpha particles? Is this comparison ...
1
vote
1answer
37 views

I thought specific activity was a property of the radionuclide?

How can specific activity of Mo-99 be higher for Mo-99 produced from fission than Mo-99 produced from neutron capture? I thought specific activity would be a property of Mo-99 so it will always be the ...
0
votes
3answers
41 views

If radioactive decay is measured by halflife does it mean that few atoms of a radioactive material are practically stable?

If radioactive decay is measured by halflife does it mean that few atoms of a radioactive material can be considered practically stable? If we try to measure the time when 0,1% of the atoms of the ...
0
votes
0answers
27 views

How does a radiation meter equipped with a Geiger-Mueller Tube measure radiation dose?

The GM-tube typically operates in saturation and an incident particle will result in total discharge. Therefore, as I understand, the height of generated pulse is independent on the energy of the ...
3
votes
3answers
133 views

How radioactive dating works? [duplicate]

Often in geology & archaeology we listen that they calculated the age of things (bones, pots) using radio active dating. Radioactive dating works using half life of unstable isotopes. And what ...
1
vote
1answer
20 views

Should all radioactive elements with HL smaller than 1000 years have 90% of their atoms already decayed on Earth?

Should all radioactive elements with HL smaller than 1000 years have 90% of their atoms already decayed on Earth? If that kind of radioactive source is found today should almost all of its atoms be ...
3
votes
4answers
108 views

Conceptual half-life Question

So I have this word problem and I’m a bit confused about it. I have the answer and explanation but I still don’t understand: The half-life of carbon-14 is approximately 5730 years, while the half-life ...
2
votes
1answer
25 views

Calculating radioactive decay

I was given the following word problem: If the half-life of a certain isotope is four years, what a fraction of a sample of that isotope will remain after 12 years? This was simple for me. 12 years ...
1
vote
1answer
27 views

Silly question: make deuterium, tritium and Oxygen-17 and Oxygen-18 from nuclear waste

Here is a silly question. Atoms of Nuclear waste isotopes usually have extra neutrons. Can regular hydrogen and oxygen come into contact with those atoms and take the extra neutrons away? Then the ...
1
vote
2answers
71 views

Radiation damage in a crystal

Take a single crystal as close to the ideal as possible, say, Si, GaAs, or SiGe, etc. Immerse the crystal in some fixed rate ionizing radiation and measure the radiation damage it has caused to the ...
0
votes
1answer
45 views

Can we uniquely determine the particles emitted in a neutron induced binary fission of a radioactive element?

Can we uniquely determine the particles emitted in a neutron induced binary fission of a radioactive element? For example, if we have $ \newcommand{\U}{\mathrm U} \newcommand{\Mo}{\mathrm{Mo}} \...
0
votes
4answers
63 views

Determining half-life of a sample

The following question is from grade $10$ science textbook: A student wants to measure the half-life of a radioactive isotope. He is told the isotope has a half-life of between $10$ and $20$ minutes. ...
0
votes
0answers
15 views

How does increasing the binding energy per nucleon release energy [duplicate]

I don’t get it. if let’s say Uranium undergoes fission to produce Barium and Krypton. Barium and Krypton will have a greater binding energy per nucleon meaning they require more energy to hold the ...
0
votes
1answer
37 views

Decay of proton to neutron [closed]

Decay of proton to neutron is-- Possible only inside nucleus 2)Not possible Always possible as it is associated with Beta+ decay I thought that mass should be conserved here, but we know that ...
0
votes
0answers
48 views

High Level Nuclear waste disposal

Can anybody please explain 50 years and 5 years that has been written over here- https://www.world-nuclear.org/information-library/nuclear-fuel-cycle/nuclear-wastes/storage-and-disposal-of-radioactive-...
0
votes
1answer
25 views

Do all radioactive isotopes and compounds exhibit photoluminesce?

I have an antique item - colored in a florescent yellow, which may be comprised of radioactive pigment like Uranium Oxide or other radionuclides I haven't a Geiger counter, but I already shined a UV ...
0
votes
2answers
49 views

Forming of helium in radioactive decay

I have just came across a question, where 1mole of Uranium (238 92) gets converted to Pb(206 82) now after balancing we get that during this decay in presence of air, 8 alpha particles and 6 beta ...
1
vote
0answers
12 views

What is the difference between areal density and attenuation coefficient?

Speaking of beta electrons, their attenuation is usually described by the areal density $\sigma$, i.e. "how much" g/cm^2 of a certain material they can pass through before stopping. I've ...
-4
votes
1answer
58 views

How to find how many atoms have to decay to get some amount of power? [closed]

How do I get the power when there is no charge, or anything else given in the question? Is there a power formula that I'm not aware of? Please help! A nucleus of plutonium-238 ($^{238}_{\ \ 94}$Pu) ...
1
vote
0answers
11 views

Can internal conversion happen at (close to) absolute zero?

My understanding is that, if an atom finds itself in an excited state, for instance following electron capture and gamma emission, the atom relaxes to the ground electronic state because of the ...
0
votes
1answer
82 views

Why doesn't nuclear fusion produce radioactive waste?

I'm trying to write a paper arguing for why we should spend more money on nuclear fusion research. I keep reading that "nuclear fusion produces no long lived radioactive waste", but when I ...
2
votes
1answer
76 views

Why is helium-3 stable?

Why is helium-3 stable? Besides hydrogen, helium-3 is the only isotope that has a neutron-to-proton ratio less than 1. Why is it not radioactive?
0
votes
1answer
35 views

Is there any significant scale nuclear transmutation currently in practice?

There was a similar question in place but the details of the answer may suggest another solution. So I am aware that transmutation is used to reprocess radionuclides in nuclear waste to render them ...
1
vote
1answer
78 views

What is the precise value of the lifetime of a neutron?

Free neutrons are unstable. It decays to proton, electron and an antineutrino via beta decay. Can we not do a quantum field theory calculation to predict the precise the decay width? Its inverse ...
0
votes
1answer
32 views

Have we observed time dilation on quickly-vibrating or very hot objects?

The common sci-fi example of time dilation would involve a futuristic spacecraft going on a one-year mission, returning to Earth 100 years later. We can imagine this happening on a smaller scale, too. ...
0
votes
2answers
37 views

Binding Energy and Stability in Nuclear fission

I've read that particles in nuclear fission disintegrates into two particles with higher binding energy, and in this process energy is released. Now I am just trying to understand this by common sense,...
3
votes
1answer
40 views

Why is aluminum more common in the solar system, etc. than sodium and fluorine?

I know that odd-numbered elements are less common than even-numbered ones, but why is aluminum more commonly created in the galaxy, apparently, than lighter odd-numbered elements? Sure, sodium and ...
0
votes
1answer
38 views

Can Uranium-238 undergo ordinary (single) beta decay?

Can U-238 undergo regular, single beta decay? Are there isotopes which can only undergo double, never single, beta decay? Not even two normal beta decays in quick succession?
0
votes
1answer
67 views

Inverse Square Law of Gamma Radiation Experiment

When performing this experiment with a cup source and GM Tube it says that you should start at a distance several times the diameter of the GM tube in order to obtain accurate results (https://www....
1
vote
1answer
20 views

Can the recoil to the nucleus induced due to radioactive decay be enough to break inter-molecular bonds?

let's say I have radioactive labelled molecule such as ${}^{99m}Tc$--Methyl diphosphonate ${}^{99m}Tc$ undergoes gamma decay and emits a photon of 140 KeV. Said molecule also forms a bond inside bones,...
1
vote
0answers
30 views

Strange behavior of Polonium — can it be accounted for by heat and/or ionizing radiation?

I have read that Polonium does things like move against air currents or migrates within containers to (I think) different parts of the container. But I also read that a .5 gram chunk will reach 500 C. ...
3
votes
3answers
376 views

How warm are radioactive metals?

I read that radium is warm to the touch -- is that because of actual heat or is that because, for example, the radiation it emits creates the sensation of warmth? How high of a temperature can a ...
0
votes
1answer
61 views

Why is 20% enrichment for uranium considered the minimum for making a nuke? [closed]

I get that this is the physical limit - an infinite mass of uranium would produce a runaway reaction. But an infinite mass is impossible. Really, what is the minimum % of enrichment of uranium which, ...
0
votes
0answers
18 views

Why is the mass defect of nuclei used while calculating the $Q$ value of decay reactions?

i just came across two questions today the first one goes like: Here the answer is calculated with (mass defect of nuclei)*C^2,why do we use the mass of nuclei to calculate Q value in this case  but ...
27
votes
2answers
9k views

Is it safe to keep uranium ore in my house?

I bought 5.6 gr of uranium ore. The measured gamma radiation is 1µSv/h, we didn't have the instruments to measure alpha/beta radiation. EDIT: The gamma radiation was measured at 1cm distance. I also ...
0
votes
1answer
182 views

Does alpha decay have anything to do with weak interaction?

In alpha decay, an atomic nucleus emits an alpha particle (identical to a helium-4 nucleus). This happens in large nuclei because the nuclear force keeping the nucleus together is outweighed by the ...
64
votes
8answers
14k views

Can 1 kilogram of radioactive material with half life of 5 years just decay in the next minute?

I wondered this since my teacher told us about half life of radioactive materials back in school. It seems intuitive to me to think this way, but I wonder if there's a deeper explanation which proves ...
0
votes
0answers
22 views

Do alpha and beta decay always emit gamma radiation?

I am looking at Ra-226 and trying to identify the decays for each peak in its gamma-ray spectroscopy spectrum. I know some alpha and beta decays emit gamma radiation but it's this always true? Can I ...
1
vote
2answers
49 views

Do all radioactive materials emit photons?

The title is simply my question. I know that alpha and beta radiation does not emit any type of photon, but all radioactive materials seems to emit some type of em radiation. Why is this?

1
2 3 4 5
12