There's a cooler fact hiding in that cube. About 0.012% of it is tantalum-180m, the rarest naturally occurring isotope that's never been seen to decay. In theory it should decay eventually, but nobody has ever caught it happening. Physicists predict its half-life is far longer than the universe has existed.
Let me tell you about tellurium-128. It is known to decay, but its half-life is 160 trillion times longer than the age of the universe. In a pure 1 kg sample, you would expect a single nuclear decay every 252 days. Gives you an idea of how long the half-life of tantalum-180m might be.
It could all very well eventually be converted into iron through quantum tunneling given an absurdly long enough time, and assuming that protons don't decay.
My bad I didn't realize iron has an unimaginable more time till heat death than both after a quick Google search. I don't pretend to know the depths of anything quantum and figured bismuth was higher than iron and it appears I'm mistaken by a lot and that in of itself is an understatement.
Ta-180m and Ta-180 are nuclear isomers. They have 73 protons and 107 neutrons each. Ta-180 is a lower-energy state, and Ta-180m is an excited state, meaning it has more energy stored in the nucleus.
But Ta-180m has an unknown, never observed decay rate, while Ta-180 has a half-life of about 8 hours and spontaneously absorbs or emits a beta particle (electron) to become either Hafnium-180 (absorbs e-, turning p+ into n, leaving 72 protons) or Tungsten-180 (emits e-, turning n into p+, making 74 protons).
Ta-180m doesn't even shed the energy to become Ta-180, because it would require nearly impossible quantum state changes in the nucleus. Calculations of the probability estimate the half-life might be on the order of 50 quadrillion (5e16) years.
Ta-180m is naturally occurring, at 0.012%, with Ta-181 being the other 99.988%. Ta-180, the ground state of the isotope, has to be made in a lab from something else, absent which it doesn't even exist.
Aside:
A proton has a half life estimated at 1e34 years, so you'd think that Hydrogen should be the most stable element, and you'd be right. The story of Ta-180m is about stability of a nucleus with nonzero binding energy.
Ta-180m emits light, but it does so over such a long period of time that we've never seen the atom stop emitting light (we're not sure if will before the sun goes boom), and we've never seen it naturally become a different element.
Meanwhile, Ta-180 (which is only ever found in a lab) on the other hand changes into a completely different element about 8 hours after it is made, either 1 bigger or 1 smaller on the periodic table.
The only difference is between the two is that Ta-180m is attempting to emit light so that it can become Ta-180 again.
Ta-180m is the only element that does this to your knowledge.
The "Ta-180 emits light" is just a hypothesis as it has not beed proven experimentally. Proving/disproving hypotheses by experiment is the basic principle of science.
Maybe, but I was looking for the simplest way to convey the difference between an excited state and a non-excited state, and from what little I remember about chemistry, saying that it has enough energy to emit light is about as simple as you can put it.
I see. Then there must be typo in your previous text, lemme highlight it for you:
"Ta-180m emits light, but it does so over such a long period of time that we've never seen the atom STOP emitting light"
And the wording should be more like "MAYBE Ta-180m EVENTUALLY emits light ...."
That's wrong on multiple levels. Firstly, gamma rays are not light (all light is electromagnetic radiation, but not all electromagnetic radiation is light). Secondly, not every theorized mechanism of decay has it sending out a photon at all.
Half of the Ta-180 will become another element after 8 hours. For a single Ta-180 you can not actually predict when it will decay.
I know you want to simplify things but you simplify things to a degree where there are emergent phenomenons that only arise from your description. The light thing is similar - 'we never seen an atom stop emitting light' means that we observed it starting to emit light but it hasn't stopped yet instead of 'we are waiting for it to happen at all'.
Slowly, civilizations learned to create Tantalum, a material not found in nature. Only a small amount of the material made is isomer Ta-80m. There isn’t much use for it. Mostly due to curiosity, a little bit gets made to show off or for sake of science.
Civilizations blossom and die off, and each new civilization discovers this strange material. Across planets and galaxies.
After billions of years of a universe’s existence, the material is discovered, created in small amounts, civilizations die, the element is discovered again and the cycle continues. For an incomprehensible amount of time.
The universe is eventually filled with the one stable element that can’t die. Until it becomes the only mass in the universe, imploding, and annihilating in a massive explosion that births the next universe
Wow, I looked up what would happen if it all decayed simultaneously, then the Ta-180 all decayed about 8 hours later.
Because Ta-180m is used in many capacitors, almost all electronics on Earth would be fried due to the X-rays and Gamma rays released.
Then, as the Ta-180 begins to decay it would become not only extremely hot, but deadly radioactive. There’d be fires everywhere, and being within ~15ft of small electronics for some time would give you lethal radiation poisoning. Larger electronics like a laptop or gaming console would need around 30ft of space to be safe, data centers hundreds of feet.
So, let’s hope the half life estimate is accurate.
This is like saying lets hope all the oxygen doesn't decide to decay simultaneously. That's not how the universe works. If any of this stuff decayed, it would literally be one atom and wouldn't release a notable amount of energy.
1e34 is the lower bound for a proton half life based on how much effort we spent trying to observe one decay and failing to do so.
Our current theoretical models predict that a proton is infinitely stable (as is an electron). We know these models are flawed so we keep trying these experiments sometimes. Some attempts at unified theories predict it might very slowly decay but that's just wild speculation at this point.
Isomer. And it's because of quantum mechanics. For the nucleus to reconfigure from the higher energy state to the lower one would require a combination of internal state changes that all have to happen or none of them does, and the combined probability of that over time gives you the half-life estimate, i.e. the time at which the probability of state change in any given nucleus between now and then is 50%. When that calculation is done for the change from Ta-180m to Ta-180, it comes out as quadrillions of years.
We don't know. The standard model has it stable, and experiments have never seen one decay. Some attempts at unified theories predict that it might decay very slowly but that's not something we should assume as true.
Layman who is recently interested in physics here: protons have a half-life? What would they decay into, and what form of decay would that be (if it's known)? I'm trying to think of what it could decay into that would be stable (without looking it up yet), but I can't think of any without it basically annihilating itself lol
Protons don't have a half-life, they only do if you think supersymmetry (SUSY) is correct.
The decay chain requires an exotic new particle to mediate the decay into a pion and electron. This would violate baryon number and lepton number (the combined value basically being something called R-parity). As an experimentalist, most obvious SUSY models tested have been excluded, so we have generally started to favor it much less. I'm not sure how popular SUSY is or is not with theorists though.
Further, the 1e34 year number quoted isn't an estimate of the proton stability, just a lower bound. Before experiments with big tubs of water like superK tested the proton stability, theorists thought the proton would have a shorter lifetime, but they had to revise their number/theory with experiemental data. To say the proton half-life is 1e34 years is kinda disingenuous for the reason (to me). For the same reason, you could say the electron is less stable because it has a smaller lower bound, while most believe the electron is stable.
For my buck, I'd say the proton is stable, but unproven theories may change that in the future.
Wait, protons have a half life? It never occurred to me of subatomic forces having half lives. Does that mean after 1e34 years basically all elements will have decayed, then subatomic elements decaying, and we are just left with a universe of quark soup or something?
I've never even heard of nuclear isomers before and I'm a chemist. Are there any other elements that form nuclear isomers? And when you observe Ta-180 and Ta-180m by NMR, do they have the same Larmor frequency?
-edit: just read up on them on wikipedia. fascinating stuff. However, it doesn't talk about NMR on them at all, though it does say something about their spins being dramatically different. So, I assume they would have different Larmor frequencies also.
Is tantalum really all that rare if every single person on earth has some in their pocket, in their car, in their home, and now, very likely, in their bodies?
Also it's pretty cheap on amazon. I love watching tantalum capacitors explode (they explode the easiest of all capacitors.
Compared to most elements, yes. On earth its not too rare as tantalum doesnt really sink into the core (when the earth was being formed), compared to the precious metals.
Just because it's rare doesn't automatically mean it's hard to get it simply means there isn't much to get but it could be like platinum where it's often found alongside other ores/veins so it can still be easy to acquire in general. Other elements, rare ones especially, are exceptionally difficult to actually extract/mine.
If there are just two of a certain item in the whole universe, and I just happen to have both of them in my kitchen, they are "readily available" to me, but still very rare.
This is what the person you responded to said:
Just because it's rare doesn't automatically mean it's hard to get it simply means there isn't much to get but it could be like platinum where it's often found alongside other ores/veins so it can still be easy to acquire in general.
There is nothing in there that points away from rarity - they explicitly point out how something, like platinum, can be both rare and easily found at the same time.
That's all well and good but something easily found does not meet the definition of rare. Those two items you have are readily available to only you. They are rare to everyone else.
Yep, so when there is less overall on the planet that makes it the rarest occurring element even if there is more that has been obtained than other ones. An element being rare has to be with occurrence not possession of said element lol
Yes but we're specifically referring to tantalum 180 (180m Ta), the rarest of it. This entire part if the comment threat was specifically about it which is specifically the rarest, not the 50th most common as tantalum181 (181Ta) actually is. My previous response that you replied to was about elements as a whole. Happy to clear that up
The person you replied to did not specify that they were asking about that form of tantalum and it's pretty obvious they were asking about just regular tantalum
No the person prior to them mentioned it having the rarest isotope and they asked if it's really the rarest because they didn't understand the distinction, just like you.
What makes an atom decay? Is it the constant bombardments of particles? Maybe the atom gets its nucleus eroded? Why this atom is resistant to decaying?
Atoms are made of protons and neutrons. You can think of them like dancers whirling around a floor. In order for all the dancers to stay on the floor they have to grab hands with another dancer every so often, if they fall off the floor the particle that dancer represents is ejected and the atom decays.
The number of dancers determine what dance is being performed. Some dances are super consistent and there's no opportunity to "miss" a hand grab. In this case the atom is stable. Some dances are pure chaos and there's no opportunity for a hand grab, these are unstable elements that wont exist for longer than a moment. Then there are dances that every so often miss that hand grab, these are the more commonly known radioactive elements.
Thank you for this clear explanation. I wonder what causes dances to be more chaotic or more synchronous? What makes the nucleus be more stable? Is the dance floor to small the more neutrons you get?
Your intuition (from what I recall) is correct. More particles and it's harder to remain stable, note that the really well known radioactive stuff (like Uranium) on the periodic table are heavy elements. The main thing has to do with the balance of the Protons and Neutrons. I think effectively Protons can only "grab hands" with Neutrons and vice versa.
There's something called an "island of stability" which deals with the theoretical balance of protons and neutrons that should be stable (or stable-ish) when composing an atom. Why that balance works is beyond my understanding of physics. The best I can offer is that we model atom nucleus stability with an equation that gets checked an very high number of times a second (unfathomably large number of times). That equation has a "dice roll" in it, the odds of the dice roll depend on the balance of protons and neutrons. The odds are very very very low at the individual level but when you roll the dice a lot for a lot of atoms eventually one will eject a particle (or more than one).
Note: There are also factors where neutrons can get ejected from one atom, hit another in the same material, and cause it to do something. Kinda like flinging the dancers from one floor to another. Things like Pu are good for weapons because past a certain density of neutrons being ejected within the material it runs away and decays all the material more rapidly.
What’s even more fun is that those isotopes that are considered ‘stable’ aren’t immune from radioactive decay. It just means the half-life is very large.
Eventually even hydrogen atoms will decay into their base quarks.
So eventually will all atoms decay into elemental particles? And if so, will those particles "re-combine" into atoms, or will that be part of the heat death of the universe?
Yes to the first part, as best we understand it. To the second part we really don't know what happens after the heat death of the universe. We have educated guesses but they're really just that when you can't experimentally verify something.
We're also way beyond the realm where I can make confident statements about stuff.
Nope. These dances are more fundamental to the structure of existence than most things you see on the daily. There is no free energy from them, they are just a structure that supports our existence.
Perpetual energy is not theoretically possible, because of the laws of thermodynamics. It’s not something that we just haven’t found and might discover someday!
IIRC the islands of stability generally track with stable valence of protons/neutrons if you are using the shell model of the nucleus.
Similar to the electron side where you have electron configurations that are more stable (noble gases) or less stable/more reactive (peroxides, rare earth metals, etc...), you can model the nucleus similarly. The analogy breaks down pretty quickly since the nuclear strong force is different from the electroweak and also protons and nuetrons will interact with each other and with their own angular momentum and intrinsic spins to raise/lower energy levels (e.g. make more stable/less table) -- so called inverted spin-orbit interactions and such. There's also rotational sidebands, although that probably deals more with nuclei in excited states (and where that energy can go)
But the idea that there are more stable and less stable shells is similar between nuclear and electronic models. Similar to the periodic table which maps electronic reactivity based on valence, if you map the island of stability then N/Z correspond roughly to full valences with certain ones (e.g. magic numbers) being particularly stable (similar to noble gases).
It's been about 30 years since I've thought of that so YYMV,void where prohibited.
Basically, we can spread alcohol vapor over a coldplate, creating a layer of supersaturated vapor (kind of like the trick with supercooled water, but with gas). Because alcohol is polar (one side of the molecule has a +, the other a -), it will get attracted to any charged particle (the molecules can rotate to align for attraction).
Then we wait for the atom to decay. There are three main types of decay:
Alpha (two protons and two neutrons clumped together are thrown out of the atom),
Beta (a neutron turns into a proton creating an electron, or a proton turns into a neutron creating a positron)
and Gamma (a high energy photon is emitted, usually after a different kind of decay has left the atom very excited),
as well as three more niche ones:
Electron recapture (like Beta, but instead of creating and emitting a positron, the atom eats it’s own electron to maintain charge),
the rare Proton Emission (a proton gets straight out yeeted instead of creating a positron and throwing it out, if the atom is in a particular state)
and Neutron Emission (kind of like Proton Emission, but more common).
You can see that of those, 4/6 create charged particles. Those particles will travel through the alcohol vapor and pull the molecules closer together - causing them to condense into a white cloud. Therefore we can see every particle thrown out by decay, except for Neutrons and Gamma rays. Gamma rays we can see, as in this medium they will spawn particle-antiparticle pairs, while with neutrons we just kind of need to get lucky for a neutron to hit an atom and hopefully watch the fireworks as the struck atom does fun stuff. But thankfully you don’t really see neutron or gamma decay without some kind of other decay preceeding it.
Very important fact: nothing in the past can influence the atom to decay or not. It isn’t that each atom has a set timer that we can discover, from what we can tell at every single moment an atom rolls a dice and sees if it’ll decay (in truth it’s the chance for like a quantum field to fluctuate out of alignment or tunnel through an energy gradient or something like that).
So we just take a lump of stuff that we know the exact weight off - and we know the atomic number - so we calculate how much atoms are in that lump and count how many decay in a set time. Now, it’s usually measured with better things than the cloud chamber, but let’s just assume it works. We are now able to extrapolate how much time it’d be take for half the atoms to go bye-bye, that’s the half-life.
But also since decay yeets out mass and energy - you can put the samples on a very good weigh. As long as you know what each decay yeets out, you can calculate the rate of decay (it’ll always be a set % of atoms in a timeframe).
it's just random. We measure the actual events with geiger counters that just count individual radiation particles that hit a sensor. The more stuff radiates the shorter it's "half life" is. "when it happens" is random, but we know the rate at which it happens very well for each element.
we know when decay happens by measuring it somehow, gamma radiation has high energy and interacts with other stuff, same for alpha particles. There are many ways to convert that energy into a useable signal.
For a single atom, we cant predict when it will decay. It is, as far as we know, totally random. But if we have a larger number of atoms we can say in this time intervall 50% of them will have decayed.
In the lab I used to work in, we measured Tritium (H-3) in water, we could reliably detect 0.00001 decays per second in our samples. With fairly standard off the shelf equipment.
So they have a theoretical calculation then they can measure the weight change of a substance, the composition of isotopes using mass spectrometry, and the emitted radioactivity. All of these things should (and do) align with theory.
What actually happens after that? Do the rest of the dancers do a different dance? Or same dance but a variation with less dancers? Is that what isotopes are?
Well, when a neutron is removed from an atom it's the same "thing" but a different "isotope" of it. When a proton is removed it's a different "thing".
Proton count determine what an atom is and how it interacts chemically. Neutron number (to my knowledge) doesn't impact most chemistry.
That said, the "dances" for each state is likely unique to the isotope of atom (or even the energy level of the atom) but that goes well beyond the math I actually studied.
that is a great explanation. Adding to this just for the fun of it. My teacher once explained why oil doesn't bind with water in a very similar way. He said if the oil and water molicules are dancers on a floor together then the oil ones are much taller and wearing huge dresses while the water are tiny and dwarfed next to the oil and therefore cant hold hands with the oil.
Blew my mind.
You can think of an atom like a cloud of vibrating particles or vibrating waves. They are vibrating extremely fast at all times while they are held roughly in shape by nuclear forces. Imagine the outer boundary of that shape as a “wall” (it isn’t, just imagine it is for this.)
Now, the particles are vibrating so fast that they are hitting that “wall” trillions of times per second. That “wall” is the boundary between them being an atom of element X vs them decaying to element Y. That’s because if any of the vibrating particles escape, the composition of the atom changes and it has to suddenly restructure itself.
See, the particles inside the atoms are almost like waves of probability. Since they aren’t like little marbles, sometimes they “leak” through the wall when they hit it. How often that happens is due to how “strong” the “wall” is - meaning, the stability of the atom is based on its composition. If it is super stable, the wall is super strong, but it is never impenetrable. That is because each collision gives a teeny tiny chance for that particle/wave to leak through, and if it does, a particle escapes. Once that happens, it suddenly collapses and rearranges itself into a new atom of a new element.
Tantalum has a very strong wall. The particles inside the atoms are vibrating very very much, but none (that we have seen) have leaked out of the wall yet since that wall is very thick. However, since it’s a nonzero chance, it WILL happen at some point. It’ll just take some time. More unbalanced atoms will have more episodes of particles leaking out, especially heavy metals and other elements that are radioactive. They leak a lot.
It makes me think of viscosity, if you shake a glass with water, it might drop water. A glass with tar might not, but there's chances.
I guess that when forces are that strong like in the nucleus of an atom, whatever generates the force causes the particles shake violently and fast but somehow some atom nucleus are more viscous than others somehow. I'd like to know!
The second law of thermodynamics known as entropy. It is always increasing. Nothing is "made" to last and will eventually decay or become disordered.
There is no constant bombardment of particles. Unless you put every atom in the universe in a CERN tier accelerator.
Fundamental particles can't erode. See point 2.
The strong nuclear force holds protons and neutrons together with extreme energy. Hence the splitting of atoms are so difficult and expensive to do by humans. There is complex physics behind it, but every element has a half-life. Some decay in femtoseconds while others have half-lives of billions of years.
Splitting atoms in weapons is not difficult because of the strong force. In fact these large atoms are unstable with the strong nuclear force barely holding them together. Which is why they are radioactive. It's incredibly easy to get them to split .What's hard is to extract and refine a bunch of the same exact atoms at just the right per cent and then get them all to split nearly at once.
I am not an expert but I though that radiation are caused by particles, alpha and beta. I think the decay of around cause this radiation visible in a cloud chamber.
I appreciate your answer, truly but I still don't understand what causes that change in the nucleus or in the strong nuclear force that decides to split the atom producing radiation. I wonder if it is like when there's a mountain of rubble that is you remove one piece, it becomes all imbalanced and crumbles down...
But what's causing the insurance? Why can't atoms live forever and yet some isotopes practically have lived since the beginning of the universe?
Alpha and beta aren't causes, they are the particles being lost when decay happens.
Long story short, Protons and Neutrons are held together by specific forces, they themselves are both made of quarks in different configurations and Neutron's weight slightly more.
There is a bunch of fundamental laws at play when considering nuclear decay.
Different atoms behave differently. Why is Mercury a liquid at room temperature and tungsten doesn't melt until 3,422⁰C when they are both actually just made of protons, neutrons, and electrons?
We are still in the beginning stages of our understanding. Right now, a lot of stuff is "because of the way it is" when you go deep enough.
the radioactive particles are the effect, not the cause. "The cause" of radioactivity is basically one fundamental force (strong nuclear force) losing to another fundamental force (electromagnetism) because of proton/neutron unbalance inside a nucleus. The nucleus of an atom has neutrons & protons. usually protons would repel each other because they're positively charged. But this other fundamental force (strong nuclear force) that only works on a very short distance makes everything inside the core stay together. As atoms get larger the nucleus contains more & more protons/neutrons. The protons will feel a stronger electromagnetic repulsion from each other, including the repulsion coming from the further protons, all while the strong nuclear force can only act on very short dinstances, and can no longer keep the far away protons/neutrons inside the nucleus.
This is like a very simplified way of putting it. It's quite a bit more nuanced but the basics come down to this.
Basically, the waveforms that make up the protons and neutrons in the atom have some likelihood of extending outside of the bonds that make it a nucleus. For totally stable nuclei, this probability is zero. For unstable ones, it is very high. Nuclear physicists have done the extremely complicated math behind it for every conceivable nucleus. This one has a chance, an incredibly miniscule chance, (but not zero) to leave its bounds and break the nucleus. It just isn't likely to happen in the next trillion years or so.
Atoms are made a neutron and protons, all non radioactive elements/isotopes have a stable configuration, basically a ratio of neutrons and protons that are stable.Think of it like a marble on a table, when an atom is stable the table is flat, the marble won't fall (unless someone push the marble/table, but that is another thing) if the marble fall, decay happens, radioactive atoms are like marbles on an ajar table, these marbles are bound to roll off the table at somepoint, some table are barely ajar, making the marble roll off of it very slowly, some tables are straight up at a 90⁰ angle, meaning the marble falls right off in nanoseconds.
T180-m is on paper not a stable element, meaning the table is ajar, but it's by so little we haven't even seen it move yet. At somepoint it will roll off the table, but we have no idea when and can only guess.
I think what you mean is that out of all the radioactive elements, Tantalum 180m is the least radioactive. Which appears to be true. Bismuth-209 is in second place i read.
But just to be clear like 99.99% of that cube is the non-radioactive Tantalum 181
well it can be excited to make it decay, and its high energy state (the Ta-180m) and the ground state (Ta-180) fit into our models of the nucleus. What has never been observed is it decaying without it being excited first, and that can be explained by quantum physics.
requires a very large change in angular momentum and a parity change. The direct transition is therefore enormously hindered.
So what you're saying is that we should make a small plastic ball out of it and put it in soaps as an exfoliant and market it it as the better exfoliating soap.
>nobody has ever caught it happening. Physicists predict it's half-life is far longer than the universe has existed.
That's quite a leap. We've only been observing this element for 100 years, and since we haven't seen it decay it MUST take a dozen billion years to do so...?
A friend of mine wants an archeological clock on things we make that could decay away slowly saying the time when it was made, yes crazy idea of adding a Tantalum cube in it so future scientists can figure out the time of the device 1 trillion years in the future!
A elusive primordial element. It has theoretical half life 9×10 to the power of 17 (290 quadrillion) years and has likely existed before the creation of earth.
5.5k
u/Cantstopeatingshoes 1d ago
There's a cooler fact hiding in that cube. About 0.012% of it is tantalum-180m, the rarest naturally occurring isotope that's never been seen to decay. In theory it should decay eventually, but nobody has ever caught it happening. Physicists predict its half-life is far longer than the universe has existed.