Questions tagged [radioactivity]
Questions relating to radioactive substances and the chemistry of radioactivity. Also, use [rare-earth-elements] if the question is about their radioactivity specifically.
148
questions
3
votes
1
answer
101
views
Why is nickel-56 not a stable nuclide?
Why is $\ce{_{28}^{56}Ni}$ not a stable nuclide?
As far as I studied radiochemistry, magical numbers of protons and neutrons correspond to the more stable elements, due to their perfectly spherical ...
1
vote
0
answers
48
views
Are these formulas for the critical value for detection interchangeable?
I am trying to compare equations for calculating the critical value for detection. One is presented by the ISO standards (https://www.sciencedirect.com/science/article/pii/S0969804316306455?via%3Dihub)...
0
votes
0
answers
87
views
Why is tritium radioactive?
The nucleus of tritium (hydrogen-3, $\ce{^3H})$ contains one proton and two neutrons. Nothing repulsive is acting on the proton that can make the nucleus unstable. Then why does it decay?
I suspect ...
- 67
3
votes
0
answers
46
views
Bonding and then breaking radioactive molecules
I was looking at Radon and noticed that it has a half-life of 3.8 days, yet still makes compounds with some other elements.
This got me wondering, are there any examples of chemical processes or ...
- 175
1
vote
1
answer
68
views
Which gamma radiation had more high-energy?
I am working on a short story centered around the Fukushima Daiichi nuclear disaster and I was wondering which $\gamma$ radiation had more high-energy: the radiation from the cooling water flowing ...
- 21
6
votes
1
answer
346
views
How do alpha particles contribute to pressure of nuclear decay products?
A closed vessel with rigid walls contains 1 mol of $_{92}\ce{U}^{238}$ and 1 mol of air at 298K. Considering complete decay of uranium to $_{82}\ce{Pb}^{206}$, the ratio of final pressure to initial ...
- 433
-1
votes
1
answer
70
views
Radioactivity in pegmatite [closed]
The site in question has pegmatite which includes uranium-bearing microlite. The age of the pegmatite is 1.3 billion years. I've measured the pegamtite at 4.2 mR/hr (see photo)
The chart below show ...
- 435
6
votes
1
answer
278
views
Stability of beryllium isotopes
I have been reading about isotopes and their abundance on Wikipedia. It states that lithium has 2 stable isotopes, beryllium has 1 stable isotope (monoisotopic and mononuclidic) and boron has 2 stable ...
- 728
2
votes
1
answer
244
views
Very Little Astatine
Astatine is the penultimate halogen in the periodic table with atomic number 85. It is very much radioactive and would vaporize itself by its own radioactivity before being collected. But there is ...
- 728
8
votes
3
answers
3k
views
How come nuclear waste is so radioactive when uranium is relatively stable with an extremely long half life?
Natural uranium has a half life of 4.5 billion years. Representing with the expression $m(0.5)^{\frac{x}{(4.5\times10^9 \times 364)}}$, where $x$ is in days and $m$ is the initial mass of uranium. In ...
- 101
1
vote
0
answers
26
views
What is the main difference in between PGNAA and PINS?
I understand that both use a neutron emitter to trigger the material being analyzed to emit gamma radiation which is then analyzed to determine the material, but what is the exact difference between ...
- 19
-2
votes
1
answer
270
views
Why does bismuth-212 decay to thallium-208? [closed]
Why does $\ce{_{83}^{212}Bi}$ decay to $\ce{_{81}^{208}Tl}?$
I know that in general the $n/p$ ratio must be less than 1.5 for the nucleus to be stable, but in this case the ratio goes from 1.55 to 1....
11
votes
2
answers
312
views
Do chemical bonds impact half-life of elements?
Let’s say we have element X with half life of 100 years. Can chemical bonds like X−X or X−Cl increase/decrease half-life of X?
As a follow up question, can it increase/decrease radioactivity of X?
- 167
7
votes
1
answer
503
views
Is the method of Benji detecting plutonium realistic in Mission Impossible: Fallout?
In Mission Impossible: Fallout, there is a scene where Benjamin Dunn was examining a plutonium core brought by Eastern European gangsters. He touched the core with some sort of a rod and when asked ...
- 25.2k
-2
votes
1
answer
106
views
Reason behind the existence of radioactive substances till now [closed]
If radioactive substances continuously radiates alpha particles, then that element would never be seen by us because it would had been converted into some stable atom a long time ago. Am I right?
1
vote
1
answer
165
views
Can eating soap protect you if you ingested radioisotopes? [closed]
In “Pass the Vegetables, Please”, the 71st episode of Gilligan's Island, Gilligan and the gang all ate seeds of radioactive vegetables, and the professor suggested eating soap. He says the ...
- 39
0
votes
1
answer
2k
views
Why is it that first order reactions never end? [duplicate]
I'm studying chemical kinetics in high school. We are studying Integrated Rate Equation of first order reactions - their derivations and graphs. Our teacher showed us a graph of:
Concentration of ...
- 17
-2
votes
2
answers
99
views
How is a beta particle an electron? [closed]
I've previously read that a beta particle is just a fast moving electron or positron that emerges out of a neutron and turns it into a proton.
I'm really confused by this since particle physics states ...
- 7
0
votes
2
answers
939
views
Neutron–proton ratio and isotope stability
I have studied that most of the isotopes (not all of them!) with a neutron–proton ratio of $\ge 1.5$ are unstable; but it is obvious that this is not true in some cases like carbon-14 or technetium-99....
- 19
4
votes
1
answer
110
views
What do the suffixes on Y-90s and Y-90v mean?
I'm writing software that needs to differentiate the following "isotopes" for a dose calibrator (as used in nuclear medicine). My software needs to normalize various inputs for "...
- 143
0
votes
0
answers
121
views
Finding half life of a given decay path given percentage decayed in each path
$^{64}_{29}\ce{Cu}$(" half life" =$12.8$ "hours" ) decay by $\beta^{-}$- emission (38%), $\beta^+$- emission(19%), and electron capture (43%). Write the decay products and ...
8
votes
2
answers
190
views
Can actinides form diamagnetic coordination complexes?
I am not sure how accurate I can predict the magnetic properties of actinide diamagnetic complexes, due to the fact that they share the F-block electron as Lanthanides, which are already tricky, ...
- 699
0
votes
1
answer
579
views
Why is the only natural source of radium compounds uranium minerals?
A common mineral of barium is barytes, or barium sulfate ($\ce{BaSO4}$). Because elements in the same periodic group have similar chemical properties, we might expect to and some radium sulfate ($\...
0
votes
1
answer
55
views
Energy per atom in a parallel radioactivity equation [closed]
I was reading an example in my textbook and the question goes like this:
In a parallel radioactive decay, find energy liberated per atom of 'A' in MeV.
The solution is proceeded like this:
$$
\...
- 71
2
votes
2
answers
1k
views
Why is tellurium-128 so stable compared to the other radioisotopes?
Tellurium-128 is the longest lived radioisotope so far with a half-life of 2.3 septillion ($2.3*10^{24}$) years. I know I've heard something about so called "magic numbers" that if you have ...
- 921
0
votes
0
answers
47
views
Where do the electrons for which RTG's use for the Seeback effect come from?
I know that RTG's use Radioactive Isotope that emit Alpha particles generally (ie. NASA uses Pu 238), I also know that these Alpha particles are consiting of 2 Protons and 2 Neutrons, since the RTG ...
-2
votes
2
answers
933
views
Why alpha-decay only occurs in elements with atomic number greater than 83? [closed]
In my textbook, it is written that $α$-decay only occurs in heavier nuclei. But why? Why is that so? There is literally no explanation given in my textbook as to why this is true. Please explain. ...
- 149
0
votes
1
answer
219
views
What is the difference between radioactive equilibrium and transient equilibrium?
Consider the following radioactive decay:
$\ce{A\rightarrow B\rightarrow C}$
In my textbook, it is written that radioactive equilibrium is when rate of formation of $\ce{B}$ is equal to rate of ...
- 149
0
votes
0
answers
60
views
How is the atomic number of a beta particle zero?
In my textbook, $\ce{β-}$ particle is denoted as $_{-1}e^0$. This means that the atomic number of $\ce{β-}$ is $\ce{-1}$. But that doesn't make any sense. Also, how is the mass number of $\ce{β-}$ ...
- 149
2
votes
1
answer
76
views
Finding half-life of a nuclide based on gas release
Full Question: The hydride of an unstable nuclide of a Group IIA metal, $\ce{MH2 (s)}$, decays by alpha emission. A $\pu{0.025 mol}$ sample of the hydride is placed in an evacuated $\pu{2.0 L}$ ...
- 31
3
votes
2
answers
304
views
Long-lived, non-lethal radioisotope for fiction [closed]
I'm writing something where the characters are looking for someone among a large set of people. They don't know who this person is and they don't know what they're looking for, so their best bet is to ...
- 187
1
vote
1
answer
129
views
Does the decay of Carbon-14 effect health in biological systems?
Please note that this is not fundamentally a Biology question. It relates to the properties of molecules containing Carbon and Nitrogen.
Carbon atoms are everywhere in living systems from sugars to ...
- 709
0
votes
1
answer
335
views
Is it accurate to describe these radiation measurement units in terms of where-it's-measured and relationship-to-time?
I'm reading about measuring radiation and trying to come up with a more intuitive retelling for an audience familiar with math but not necessarily chemistry or any physical science. Is any or all of ...
- 101
-4
votes
1
answer
90
views
Could there ever be a way to safely handle visible amounts of elements like astatine, francium, or protactinium? [closed]
This is something I'd actually be interested in doing if possible. I've asked about artificial stability here https://physics.stackexchange.com/questions/584595/could-there-at-least-theoretically-ever-...
- 13
1
vote
2
answers
349
views
What lab equipment did Marie Curie use to isolate radium?
My experience in growing crystals for condensed matter physics has been sealing grams of material in ampoules which get heated in laboratory furnaces, so I don't have the experience to understand how ...
- 607
9
votes
1
answer
521
views
How are organic compounds with radioactive atoms synthesized? [closed]
We often see reactions such as these in textbooks to highlight how reaction mechanisms work:
How are the radioactive substrates required for these mechanisms synthesized in the first place? There ...
- 6,218
8
votes
2
answers
2k
views
Kinetics of a simultaneous parallel radioactive decay
Question:
A radioactive isotope, A undergoes simultaneous decay to different nuclei as:
\begin{array}{cc}
\ce{A->P}&\,(t_{1/2}=9\ \mathrm h)\\
\ce{A->Q}&\,(t_{1/2}=4.5\ \mathrm h)
\end{...
- 103
18
votes
3
answers
7k
views
Why can radioactive contamination be spread by people?
So I am reading a book called "Voices from Chernobyl" where witnesses, nuclear plant workers, firefighters and other persons involved in the 1986 accident give testimony of their experiences....
- 301
23
votes
3
answers
5k
views
How toxic chemically is plutonium (Pu), neglecting the radioactive damage?
In Rhodes' The Making of the Atomic Bomb, he says that, while Pu is not that radioactive (which is surprising -- maybe he means compared with radium and some other elements), it is very toxic.
I would ...
- 461
0
votes
1
answer
97
views
How are half lifes calculated for radioactive substances that decay over many years [duplicate]
How are the half lives (or whole lives) calculated for slowly decaying radioactive substances such as tellurium? I must be having a fundamental misunderstanding of how we are able to predict the ...
- 119
1
vote
2
answers
608
views
Why is an atom with excess neutrons unstable? [duplicate]
In this chart, I can see that stable nuclides (other than hydrogen) have a neutron count greater than or equal to their proton count, and that the neutron:proton ratio for stable nuclides increases ...
- 187
-3
votes
1
answer
114
views
Radioactive decay of ions in solution [closed]
What happens when ionic salts in solution decays? For example, if I had a handful of Francium-223 Palmitate(Francium salt of palmitic acid) and I were to put it in solution, how would the francium ...
3
votes
1
answer
109
views
Has the half-life of an isotope ever been accurately predicted before it could be measured?
The half lives of many radioactive isotopes have been measured directly. But are their half-lives known to be a function of their composition?
In other words, can someone say "given an atom with this ...
- 187
1
vote
4
answers
7k
views
Determining Half-lifes from a graph
So I was studying for an exam I have thursday when I came across a question regarding half-life. I had previously thought that the definition of a half-life is the time it takes for the amount of ...
- 378
0
votes
0
answers
29
views
Do radioisotopes emitted particles influence their chemistry? [duplicate]
Supposedly, a isotopes have the same chemistry, i.e. how they bond to other atoms. Is this true for radioisotopes? I can imagine a nucleus emitting particles that interact with existing bonds in its ...
- 864
-2
votes
2
answers
2k
views
In the reaction mentioned what percentage of reaction proceeds via SN1 mechanism?
2-iodo butane (having radioactive iodine) reacts with KI (having non radioactive iodine). Rate of loss of optical activity was 1.96 times the rate of loss of radioactivity. What percentage of reaction ...
- 15
-1
votes
1
answer
112
views
If every radioisotope atom in your body decayed at once, would you explode? What are the odds of it happening spontaneously? [closed]
The title pretty much sums it all.
- 663
0
votes
2
answers
518
views
how can carbon dating even work? Its at atomic level! [duplicate]
I am a homeschooling parent, so pardon me asking stupid questions.
Everywhere I read, it is said carbon based lifeforms eat carbon and after their death that atom starts a decay.
But what I cannot ...
- 119
8
votes
3
answers
2k
views
Why does radiocarbon dating only work in nonliving creatures? [duplicate]
I understand how carbon dating works, though I do not understand why it doesn't happen while a creature is living. Because while we are alive we still have carbon 14 in us, so shouldn't it work?
- 89
0
votes
0
answers
29
views
Can the presence of radon (Rn-222) be determined by testing dust?
If a relatively unventilated area, like a basement, were to be exposed to radon gas (Rn-222), would the dust in the area possess a detectable amount of lead? Considering lead 214 is a decay product of ...
- 101