one of several states of a chemical element differing only in the number of neutrons present in the nucleus.

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Where to get the AME2012 isotope mass table?

what's the official site for getting the latest isotope mass table, i.e., AME2012? All links I have found (NIST, IAEA) point me to a site at the Chinese Academy of Sciences, but the link ...
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3answers
1k views

Why do the waters of the different oceans of the world have different ratios of their H and O isotopes?

I was reading about the Kelvin, then water, which defines it, so I ended up reading about the VSMOW. It's based on "average" ocean water. From ...
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19 views

Is the spontaneous fission-yield curve for 240Pu known?

I have not seen any data for the isotopes produced by spontaneous fission of plutonium. I believe this will be dominated by 240Pu as the major even-numbered isotope produced in reactor operations. I ...
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1answer
30 views

Medical Radioisotopes

Technetium -99 can travel though the blood stream. A detector outside the patient's body detects gamma rays, and uses this to form a picture of a flow of blood. Technetium has a half life of 6 hours. ...
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1k views

Why is it so hard to separate isotopes?

I was reading on Wikipedia that heavy water in large amounts is toxic to eukaryotic cells because certain physical properties of deuterium are different enough from those of common protium to disrupt ...
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3answers
181 views

Why U235 over U238?

There are 3 isotopes of uranium that can be found in nature[1]: U234, U235 and U238. For a chain reaction to last there must be a high amount of neutrons contents and by comparison, U238 contains 92 ...
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3answers
5k views

Is it possible that every single isotope is radioactive, and isotopes which we call stable are actually unstable but have an extremely long half-life?

I've read that tellurium-128 has an half-life of $2.2 \times 10^{24}$ years, much bigger than the age of the universe. So I've thought that maybe every single isotope of every single atom are ...
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2answers
108 views

Is there a maximum number of neutrons of an isotope?

I wondered whether there is a maximum number of neutrons in an isotope. Or is there no maximum number? So, can an H-75 atom exist?
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1answer
28 views

What is “$f$” in deuterium-hydrogen ratio measurements?

On D-H ratio plots, $f$ seems to be used as a reference point, e.g. on the right axis in this plot of D/H ratios around the solar system from a 67/P paper: What exactly is $f$ and how is it ...
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1answer
154 views

Polonium tea emergency [closed]

Let's assume that I just realised that tea I drunk 30 minutes ago during meeting with a secret agent was doped with radioactive polonium. What should I do? What the doctors will do? Are there ...
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2answers
173 views

What is the difference between the shapes of molecules with different isotopes

I'll explain my question on example of water molecule. Let us have three water molecules: normal water $H_2 O$, heavy water $D_2 O$ and semiheavy water $HDO$. Is there any difference between the ...
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1answer
73 views

With these two elements how can the isotope half-life be determined using first order kinetics?

With these two elements how can the isotope half-life be determined using first order kinetics? nobelium-259 half-life recorded @ 58 minutes fermium-253 half-life recorded @ 3 days Although I do not ...
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1answer
109 views

What is the half-life threshold for an isotope to be considered stable?

What minimum half-life an isotope should have to be considered stable?
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1answer
593 views

Is a free proton a positive Hydrogen-1 ion?

The Hydrogen-1 isotope is a form of hydrogen with 1 electron, 1 proton, and 0 neutrons. If that isotope were to lose its electron (thus being a Hydrogen-1 ion with a positive charge) what would be ...
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1answer
50 views

Does KI have to be a salt of stable I-127 isotope?

I was recently watching a TV show where some people exposed to radiation were asked to take KI. I googled for the information and discovered this and also the Wikipedia article. From what I read, I ...
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1answer
46 views

Different kinds of the same isotope

I apologize if this is an obvious question, but I can't find the answer anywhere. In this page: http://ie.lbl.gov/education/parent/U_iso.htm are listed the isotopes of Uranium. Some of them, for ...
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31 views

Quantum Mechanisms for Isotope Fractionation

Are there any quantum properties that would enable isotope fractionation? For example, atoms with odd versus even numbers of neutrons are fermions and bosons, respectively. Has any work been done ...
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1answer
2k views

Absolute isotope activity in a nuclear fallout

I've seen nice graph showing relative activity of each isotope in Chernobyl fallout: Could anyone suggest similar graph or raw data but for absolute isotope activity for the case of nuclear ...
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1answer
146 views

How to solve the Fukushima incident?

I am trying to find out if it is somehow possible to take all this nuclear material, put it in some type of gamma chamber or blast it with neutrons to change the uranium isotopes into something ...
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49 views

How do you determine the energy of an isotope?

How do you determine the energy of an isotope? I there a calculation for it? Sorry for the confusion
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3answers
64k views

Why can Hiroshima be inhabited when Chernobyl cannot?

There was an atomic bomb dropped in Hiroshima, but today there are residents in Hiroshima. However, in Chernobyl, where there was a nuclear reactor meltdown, there are no residents living today (or ...
3
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1answer
186 views

Why does the metastable form of Technetium-95 have a longer half-life than its most stable state?

I was looking at the isotopes of technetium page on Wikipedia recently, and it seems that the metastable ${^{95m}Tc}$ has a substantially longer half-life (61d) than its most stable state of ...
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1answer
64 views

Isotope exchange between heavy water and plastic container

It is known that pure heavy water will quickly get contaminated by light hydrogen atoms if exposed to air due to isotope exchange. Does the same thing happens when heavy water is stored in plastic ...
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2answers
3k views

Is it possible to speed up radioactive decay rates? [duplicate]

Possible Duplicate: Do some half-lives change over time? Would it be possible to considerably speed up the decay rate of an isotope? Considerably meaning more then a 1 or 2% increase in ...
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3answers
7k views

Why is technetium unstable?

Is there a simple account of why technetium is unstable? From the Isotopes section of Wikipedia's article on Technetium: Technetium, with atomic number (denoted Z) 43, is the lowest-numbered ...
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0answers
113 views

The force exerted by a ~10 Tesla magnet on a C13 isotope?

How much force would a ~10 Tesla magnet exert on a weakly magnetic C13 isotope? If I made a molecule of diamond with $N$ C13 atoms, how large would $N$ need to be for me to pull on it with something ...
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2answers
344 views

Is there a direct relationship between an isotope's neutron count and radioactivity?

In my textbook, it lists isotopes of Carbon: C-12, C-13, and C-14. It noted that C-14 is radioactive (C-12 and C-13 are not). Is there a direct relationship between the number of neutrons and an ...
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1answer
400 views

Unknown isotope

Problem description: The most common isotope of a single nucleus stripped of its electrons is accelerated through a potential difference of 1225V and fired horizontally into a B-field directed ...
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2answers
271 views

Is it viable to convert nuclear waste into safe isotopes?

I read that powerful pulsed lasers can change isotopes: J. Magill, et. al.: "Laser transmutation of iodine-129". Did anyone estimate what would be the energy costs to transmutate 1 kg of fission ...
4
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1answer
356 views

Dangerous dose of I-131?

I was searching a lot and could only find dosages for curing cancer and allowed emission, but no Iodine-131 dose that could be connected with increased thyroid cancer risk (like, 10mSv is the ...
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2answers
265 views

Isotope properties plotting tool?

I'm looking for something that will generate scatter plots comparing different properties of isotopes. Ideally I'd like some web page that lets me select axis and click go but a CSV file with lost of ...
11
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3answers
1k views

Why some nuclei with “magic” numbers of neutrons have a half-life less than their neighbor isotopes?

It's easy to find the "magic" numbers of neutrons on the diagrams of alpha-decay energy: 82, 126, 152, 162. Such "magic" nuclei should be more stable than their neighbors. But why some nuclei ...
7
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1answer
482 views

Obtaining isotope stability

For a given isotope, one can obtain the binding energy using the semi-empirical mass formula. For example, has a binding energy of 1782.8 MeV. From this information, how can the likelihood of the ...