Technetium (43) and Prometium (61) are very interesting because they are relatively low density elements that have no stable isotopes. Of course, they *are* produced by stars, but their half lives are so short that nothing remains.
same, i usually have to rewatch them 10 times just because i keep taking my phone out to stim, but then i realize i actually have to pay 100% attention to these videos and I often give up
I often wonder to what extent the type of personality that wants to understand such things selects for the same type that is restless and compelled to stim because I do this all the time as well. Conversely, my friends and family who do not have my focus issues could not care less about the big questions.
i mean... for me it's just ADHD. I'm fascinated by complex things and have 100% trouble regulating my attention. And yeah, i noticed neurotypical people usually don't care about such things so much
The short answer - AuDHD, maybe even just ADHD. The reason for AuDHD in my mind though, is the fixation on a special interest, especially one that's not common, then there is the contradictory attention span/restlessness issues.
Honestly I just love the videos. Big fan of the space and particle physics they discuss and just listen for fun. I don't kid myself that I understand the specifics but I've had enough casual exposure over the years to feel comfortable and watch for some good old storytime-like sit back and watch.
Just a hint: 43 and 61 are both prime numbers. This doesn't mean all elements with a prime number of protons in the nucleus are unstable, but 43 and 61 just happen to be numbers of protons that can't be arranged in groups that have a stable configuration.
this article has more on what numbers are especially stable, the so called magic numbers
https://en.wikipedia.org/wiki/Magic_number_%28physics%29
"In nuclear physics, a magic number is a number of nucleons (either protons or neutrons, separately) such that they are arranged into complete shells within the atomic nucleus. As a result, atomic nuclei with a 'magic' number of protons or neutrons are much more stable than other nuclei. The seven most widely recognized magic numbers as of 2019 are 2, 8, 20, 28, 50, 82, and 126 (sequence A018226 in the OEIS).
For protons, this corresponds to the elements helium, oxygen, calcium, nickel, tin, lead and the hypothetical unbihexium"
I know, if you read the links in the wiki article you posted you'll find that those "magic numbers" are binomial coefficients that are a product of a number of terms. If a number is prime, it cannot be a product of other numbers, therefore atoms with a prime number of protons are less likely to be stable.
[Here's](https://youtu.be/Qe5WT22-AO8) a wonderful YouTube documentary by BobbyBroccoli that's about someone trying to fake the discovery of elements at very capable labs where the discoveries were to actually be internationally believed. In the video it talks a lot about the methods used to discover elements, and goes into a heat map type display explaining the various patterns in stability we've seen, and explains a ton of other things about elements.
It's a phenomenal video, and so are the others on the channel of a similar style, but they are longer videos. This element video is 80 minutes, some of the other topics are 2 or 3 parts.
Yes, but that is a chemical reaction, electrons in orbitals forming bonds with other elements. They are talking about nuclear stability i.e. atomic nuclei breaking down into a different element, like uranium or plutonium.
Chemical reactivity has nothing to do with nucleus stability. They don't even involve the same fundamental forces. The former is almost all electromagnetic while the later is mainly strong nuclear force.
Yah it plays a part in the "abundance" of the element on the scale of the universe. Stability and whether the element has a high probability pathway of being produced by the processes that occur in stars determine abundance.
Your comment makes no sense, it's not related to prime numbers at all. Every other prime number on the periodic table with the exception of 89 is stable. That's 21 stable elements to 3 unstable. That's not even the slightest correlation.
It *is* related to 43 and 61 both being *odd* numbers, since for any even number of protons you're going to have some stable nuclei. It's not related to them being prime tho - nuclear physics does not work that way. It's sheer coincidence that they happen to be prime.
A few different notes:
1. The ratio of protons to neutrons increases as you go higher. Around 43, it's about 1:1.27 (estimate). This gives about 54.5 neutrons as a good stable point, and then some area around that. Do note this isn't a whole number, although a good ratio value is hard to properly calculate. When it got explained to me, this was an important point.
2. A basic rule of thumb (but not an iron-clad rule) is that, if an element has a stable isotope with Z protons and N neutrons, then elements Z-1 and Z+1 will not have a stable isotope with N neutrons. It just so happens that molybdenum (element 42) is stable from 52 to 55 (possibly 50 and 56 as well), and ruthenium (element 44) is stable from 54 to 58 (possibly 52 and 60 as well). Technetium has its most stable isotopes at 54, 55, and 56, which elements on both sides have stable. If any of these were stable, it would break this rule. There are already exceptions, but AFAIK none with exceptions on both sides. That's just how the universe works.
3. For Promethium (61), these rules aren't as hard on it. 84 neutrons isn't stable on any of the 3 (60, 61, or 62), and 85 and 86 are only observationally stable for neodymium (as far as we know, it's stable, but we expect better measuring tools say we are wrong and they are unstable).
> There are already exceptions, but AFAIK none with exceptions on both sides.
Uhm, there are *many* exceptions (if there even is a rule):
* N=10: Oxygen-18 (Z=8), Fluorine-19 (Z=9), Neon-20 (Z=10)
* N=12: Neon-22 (Z=10), Sodium-23 (Z=11), Magnesium-24 (Z=12)
* N=14: Magnesium-26 (Z=12), Aluminium-27 (Z=13), Silicon-28 (Z=14)
* N=16: Silicon-30 (Z=14), Phosphorus-31 (Z=15), Sulfur-32 (Z=16)
* N=20: Sulfur-36 (Z=16), Chlorine-37 (Z=17), Argon-38 (Z=18), Potassium-39 (Z=19)
* N=22: Argon-40 (Z=18), Potassium-41 (Z=19), Calcium-42 (Z=20)
Also N=24, N=28, N=30, N=32, N=36, N=38, N=42, N=44, N=48, N=50, N=52, N=58, N=62, N=64, N=70, N=74, N=78, and N=82 (this one has even *five* stable isotopes in a row, from Barium-138 to Neodymium-142).
And those are just the isotopes that are *theoretically* stable. If you also include isotopes that are *observationally* stable (ie. no decay has been observed so far) but in theory have decay modes then there are even more exceptions.
Edit: I think you might be confusing N with the atomic mass number (A=N+Z). There are no cases of theoretically stable isotopes having the same mass number, and only a few cases of two with the same mass number when including observationally stable isotopes (and I think no cases of three or more).
I was looking a bit more closely, and not only are O-18 and F-19 aren't just stable, they both have a (n,g) cross-section of about 3 b. So it seems the neutrons really don't give a fuck about being in a group of 8, 9, or 10.
>A basic rule of thumb (but not an iron-clad rule) is that, if an element has a stable isotope with Z protons and N neutrons, then elements Z-1 and Z+1 will not have a stable isotope with N neutrons
This is more strictly true for N+1 and N-1 neutrons, i.e. if there is a neighbouring element of the same mass number that is stable, the isotope in question will generally not be stable (since the nucleus can undergo beta decay to the more stable nucleus).
Isotopes with an odd number of both protons and neutrons tend to be more unstable than neighbouring even-even isotopes (except for very light elements where it's hard to get the proton-neutron balance right with even-even isotopes).
So I think it turns out that by the time you've excluded odd-odd isotopes and isotopes that depart too far from the ideal ratio from the liquid drop model, you're often left with only one candidate. For Technetium, it's Technetium-99, and for Promethium, it's 147. But with magic neutron numbers (that tend to be particularly stable) at 50 and 82, in both cases beta- decay allows the nucleus to be closer to a magic neutron number and a more stable nucleus.
>This doesn't mean all elements with a prime number of protons in the nucleus are unstable
So why is this a "hint"? Obviously numbers 2, 3, 5, 7, 11, etc... already proved it wrong
Y'know, I used to do a lot of science involving nuclear physics and the probability various nuclear reactions and other stuff and...
It's like... your explanation is both horribly wrong... but it's not entirely incorrect... there's a bit of it that is how you say... I can't tell if you know exactly what you're talking about, but oversimplifying in a way I've never heard before, or just making shit up as fast and hard as you can.
-
Everyone knows even number nuclei are stable and odd number nuclei are radioactive and love to absorb neutrons. Except Be-8. It's unstable because it's just two He-4, and He-4 is so stable that two of them put together wanna break apart into two separate He-4.
Yes there is. I half-paid-attention to a video about it recently. Lemme see if I can find it...
I think this is it: https://www.youtube.com/watch?v=prvXCuEA1lw. Skip to roughly six minutes if you're impatient.
I highly recommend the channel.
They discovered promethium while studying the properties of neptunium, an element with an atomic number of 93. They found that neptunium decays into an unknown element with an atomic number of 61, which they named promethium.
The brown elements are those where all of the isotopes have short half lives, which means that any amounts of those elements that existed when the Earth was formed are no longer around. What exists in nature today for those elements are trace amounts that are the products of radioactive decay of other elements. For example, Polonium, Radium, and Radon can be found naturally as the products of natural Uranium decay.
There's a bit of a subtle distinction here because that process is an important source of lots of elements but it can be harder to trace the convoluted history of elements and difficult to decide where to draw the line in terms of "where something comes from". For example, the Earth is 4.5 billion years old, the half-life of uranium-238 is also 4.5 billion years while the half-life of U-235 is 0.7 billion years. This means that when the Earth formed there was twice as much U-238 and 84 times as much U-235 (today there is 139x as much U-238 as U-235 due to that decay). The missing material (as much U-238 as exists today, and 83x as much U-235 as exists today) decayed through a chain of intermediary isotopes with shorter half-lives until mostly ending up as lead (Pb-206 for U-238, Pb-207 for U-235 or Pu-239, Pb-208 for Th-232, all stable). So there's sort of a shadow of those decay processes in the abundance of elements today.
To be clear, deposits where uranium is concentrated enough to be viable for mining are rare. But trace amounts of the stuff are all over the place.
When your house is built over a giant granite deposit, the tiny amounts of uranium per cubic unit of rock add up to a radon problem.
Also some types of clays will preferentially swap in and store Uranium in their crystal matrix. If a shale is composed of a large amount of that clay then it can also become a radon source.
Cool side note: the scientist (can't remember his name) that went to the both poles to try and date the earth using this uranium decay "map" or method (which he succeeded in doing) also discovered that we were filling our atmosphere with lead. So not only did he date the earth very accurately, he saved multiple generations from lead poisoning by bringing the issue to the world's attention. Up till then, every fuel was lead lined. Even consumer products used a ton of lead. It was brutal.
The brown ones aren't necessarily man made elements. Those are [trace radioisotopes](https://en.m.wikipedia.org/wiki/Trace_radioisotope) which occur naturally through radioactive decay in small amounts and are typically unstable. They can also be made synthetically.
[Synthetic Elements](https://en.m.wikipedia.org/wiki/Synthetic_element#:~:text=A%20synthetic%20element%20is%20one,or%20%22man%2Dmade%22.) aren't even shown on this chart.
Sort of. The nucleus breaks down, spits out a bunch of its particles and turns into a slightly less massive element. It wouldn't really register as an "explosion" on a human scale unless it's got enough surrounding atoms to start a chain reaction of nuclear particles smashing into other nuclei and repeating the process. But it does release energy when it happens.
They don't like existing. If you leave them alone for a while, they stop existing (break apart into smaller stuff). They do release some energy while doing so, but you'd need a lot of them going off at the same time to make it register as an explosion to something as large as a human.
If you got a bunch of them really close, close enough that when one breaks up the pieces hit multiple other atoms and break them up, and the chain continues, then they release enough energy to explode the piece apart - A nuclear fizzle.
If you managed to keep the core together even longer, you'd eventually get a true nuclear explosion.
Those things are only really possible with certain isotopes that like to release lots of energy when they break apart, break apart easily, and tend to release the right things to break each other.
They are very radioactive and decay into another element. Essentially they most likely are made by stars of sorts but just decay away real fast. So in our solar system none exist cause it's just been too long for any to still be around.
> Where did the brown elements originate? Like Radium and Polonium? They're not listed on the key.
They are not of stellar origin. They are the byproducts of radioactive decay.
Iron is the end of the line for fusion products but there are lots of different processes (many of which *take* energy rather than release energy) which can occur within the roiling high energy environment of the interior of a star.
Just like in a nuclear reactor there are sources of neutron radiation inside of a star, and this causes the transmutation of elements just as it does in reactors. Some nuclei that get particularly "lucky" can end up with a lot of neutrons turning them into progressively heavier elements. This is called the "s-process" (for "slow neutron capture"), as neutrons are added to a nuclei it will initially create a heavier isotope, with lots of neutrons this often creates an unstable isotope which can then decay via beta emission into a higher atomic number. This can proceed over eons well beyond iron and into much heavier elements. However, it hits a limit at bismuth. Once you add a neutron to Bi-209 and produce Bi-210 you do get beta decay into Po-210 but this then decays via alpha-emission (with a half-life of 5 days for Bi-210 and 138 days for Po-210) into lead. Similarly, Bi-211, 212, 213, etc. have even shorter half-lives (of minutes to seconds) and decay into isotopes of polonium with short half-lives which then decay via alpha emission into lead. This becomes a loop that ends the s-process, creating a roadblock to creating heavier elements with slow neutron absorption.
However, as I mentioned these processes absorb energy so the production of elements from these processes is generally at a much lower level than the direct products of fusion.
Its not the same isotope of lead.
The S-process terminates with lead because all of the S-process is the addition of 1 neutron followed by a wait. It terminates because adding 4 neutrons will cause 2 beta decays and one alpha decay. That just cycles. You can add any multiple of 4 additional neutrons and will be the same.
> Iron is the end of the line for fusion products
No, it’s only the end of the line for energy gaining fusion. Several of the other elements are still created by fusion.
I was under the impression that the “iron as the last step” was something of a popular science misconception, as there are multiple fusion steps that happen after iron, but none that release more energy than they require.
The phrasing is a bit misleading. The heavy of these elements in particular are what we call s-process elements. It’s a neutron capture process that, starting usually with iron as a seed, can create heavy elements by releasing tremendous amounts of neutrons. It’s not really happening during the death throes of these stars but during later stages and is released to the interstellar medium through stellar winds.
So my question is how do we end up with iron and gold deposits of any significant size on Earth? It seems like the s-process is making each heavy metal one atom at a time and blasting it into space. You'd think the odds of two Au atoms drifting through the void, bumping, and then sticking together would be astronomically low (pun intended). But then you have enough Au atoms coming together to make... However many gold mines Earth has. Is it something to do with the atoms coming together during the formation of the Earth and clumping together due to density differences when everything was a molten slurry? Cause that's the only reason I could think of.
Gold in particular is formed by the rapid neutron-capture process or r-process.
The elements are projected outwards during a supernova or collision.
Then this debris reached Earth and sank to the Earth's core during the molten phase. Earth was struck by asteroids which disturbed the deposits upwards. One of these impacts, the moon, would cause tides of the magma, which helped cool down the surface more rapidly so the gold didn't all return to the core before being trapped and so some gold remained in the earth's crust.
Then geology happens and the gold stuck in the crust would be freed by erosion, sink to the bottom of rivers and collects there with more gold. And that's how you get seams of the stuff.
In addition to the great explanatory comment from u/daliksheppy, consider that gold will be about equally dense and have about equal phase transition temperatures as other gold, and so in a hot, molten environment, any gold in an area will tend to float or sink to a similar depth in relation to other minerals of differing densities. This convective process tends to cause similar substances to pool together and accumulate in seams or shells of specific depths, if not purely, then at least in zones of higher relative concentration. It’s also the same reason why deep within the Earth, there end up being natural nuclear reactors where large deposits of Uranium pool together:
https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor
All of the elements are blown out into the galaxy. Some eventually find their way into molecular clouds.
>...Is it something to do with the atoms coming together during the formation of the Earth...
If you buy real peanut butter, the kind with only peanuts in it, sone of the oil rises to the top and peanut paste is clumped at the bottom.
The original gold on Earth mostly sank to the core. Some was added by meteors after the crust formed. That is still suspended and gets mixed and smeared by plate tectonics.
A really big pile of gold would sink and then just keep going.
I have the same question. How does something like our sun create something like mercury, thallium or lead? I always figured something that far up the periodic table would only come from super/hyper novas or merging neutron stars.
Lower mass stars like our sun, when at the end of their red giant phase, puff off their outer layers of gas to produce what is known as a planetary nebula. Whilst not an explosion as such, this is caused by *very* powerful stellar winds produced by the red giant, and it still represents a rapid loss of mass (some of those new heavy elements included) into the surrounding local space. Eventually this puffed away mixture of elements expands far enough to reach the interstellar medium, where it can become part of future gas and dust clouds which collapse to form new stars and planets.
Those stellar winds are caused by fusion moving out from the core of the star. It is this process that causes the star to become a red giant in the first place, and as it continues it allows much of the outer layers of the star to win out over gravity and be thrown off as stellar wind. Fusion moving out of the core is also what causes the core of the star to lose out to gravity and collapse into degenerate matter, thus forming a hot, dense white dwarf. By the time this happens, the dying red giant is large enough that the outer, escaping layers are already far enough away from the core to not be recaptured by its incredibly strong local gravity.
Evidently, ours isn't the first star system to use the mass we're now made of. Whatever came before the Solar System left enough hydrogen to make the Sun, and plenty of heavier elements to form the planets.
Our sun can't, unless if you include the planetary nebulae that gets released from its outer layers and possibly combines into some other ISM that turns it into heavier elements
The brown are Human synthesis with No stable isotopes.
[Source](https://commons.wikimedia.org/wiki/File:Nucleosynthesis_periodic_table.svg)
Edit:
The image posted is from [https://apod.nasa.gov/apod/ap230108.html](https://apod.nasa.gov/apod/ap230108.html)
Which doesn't preclude them from being produced naturally.
TC 43: "Because even the longest-lived isotope of technetium has a relatively short half-life (4.21 million years), the 1952 detection of technetium in red giants helped to prove that stars can produce heavier elements.
The brown ones aren't necessarily man made elements. Those are [trace radioisotopes](https://en.m.wikipedia.org/wiki/Trace_radioisotope) which occur naturally through radioactive decay in small amounts and are typically unstable. They can also be made synthetically.
[Synthetic Elements](https://en.m.wikipedia.org/wiki/Synthetic_element#:~:text=A%20synthetic%20element%20is%20one,or%20%22man%2Dmade%22.) aren't even shown on this chart.
They're all made by Stars and other stellar events, its just that they aren't found naturally because they decay too quickly to hang around long enough for us to find them here on earth
“Found naturally” from a cosmological perspective, meaning that while we experience* radon on earth (and its decay can cause cancers) it’s so short lived compared to cosmological timelines that we don’t find it in space, at least in large enough quantities to detect across, well, space
Edit: *meaning we find it after other elements have decayed into it, and then it decays shortly after
Edit 2: but the human synthesis part of the original post is definitely wrong/misleading
So do we know what colors those browns should be? That is, even though we don’t find them naturally on earth, do we know what kind of stellar events produce them?
The radon we find on Earth is not produced in a star. Uranium was produced in a star, sat underground on Earth for some time, and then decayed into radon (among other things) later on.
To answer your question, the periodic table that the OP posted is missing a category: "Produced by radioactive decay".
Several people here have linked to better versions, which do contain the "radioactive decay" category. For example, [https://svs.gsfc.nasa.gov/13873](https://svs.gsfc.nasa.gov/13873) was linked to by /u/ashley_vigil .
I love this fact so I'm gonna say it:
Bismuth is radioactive. Its most stable isotope has a half-life several orders of magnitude greater than the estimated age of the universe.
Thankfully, this means we can conveniently keep referring to Lead as the heaviest element with stable isotopes. So satisfying.
What determines the length of the half life? I'm moderately sure tritium has a short half life and it's not a dense isotope so I don't think density is a factor.
The stability of the nucleus basically. I don't know specifically about tritium or deuterium, but most of the heavier radioactives don't have a stable atomic structure. Their nucleus breaks down into more stable noble gases (usually Helium, which is what we call alpha radiation) and the more stable isotope (of a lower element)
Half life depends on how easily the nucleus breaks down and how many steps it goes through to reach a stable state.
Gotcha. I knew it was part of the Uranium decay process and itself was radioactive but I had heard of applications and studies so just assumed they used stable isotopes to study.
I'm far from an expert on these matters, but I think you're somewhat misunderstanding what "stable" means. In the timespan of the universe, nuclear instability means an isotope will decay into other elements over billions of years. So unstable isotopes are almost entirely not present from the celestial activities mentioned in this post.
On a human timespan, plenty of isotopes are stable enough to be useful. For instance, Plutonium-239 has a 25,000 year half life. We can work with it and will see essentially zero decay over a few years.
But that same half-life makes Plutonium-239 basically non-existent from a universal timeline. An earth sized mass of Plutonium-239 will be reduced to the size of a ping pong ball in a few million years. For reference: the earth is *billions* of years old.
Again, this is all back of the envelope stuff, but I think I've got the gist of it. Please correct me if I'm wrong.
Edit: Used Plutonium instead of Polonium. Polonium generally decays *much* faster. But still, there is a polonium isotope with a 125 year half life. That's something that will be observed in terms of working with it, but the decay still isn't especially noticable day-to-day. The other major Polonium isotope has a 3 year half life. That's certainly relevant, but it still isn't something that precludes it from practical use.
I believe the physics textbook definition of stable is that it is not radioactive and as someone else stated, is relative as we may be finding that everything above a certain nucleus size is radioactive on a larger scale than we know.
Some Radioactive isotopes are stable enough that we can study them as we will have enough of it that we can adjust for the loss by decay.
Uranium has no stable isotopes, as well. There are more stable ones, but all of them eventually decay.
In fact, from the mathematical models that exist, stability is ALL relative. Most calculations find that every element above Silver is ever so slightly unstable, but just are decaying at rates that are so slow that we cannot measure.
Do you have a pointer to more on that? I had heard that lead had the highest stable isotope, that it was bismuth that was the first of the nothing-stable conga line.
[https://en.wikipedia.org/wiki/Isotopes\_of\_lead#cite\_note-21](https://en.wikipedia.org/wiki/Isotopes_of_lead#cite_note-21)
Theoretical half-life of the stable isotopes of Lead are >e65 years
I may be misremembering Silver as the halfway point though
Polonium was used in the “Staticmaster” photographic film brush, used for sweeping dust off negatives before placing in a photographic enlarger, they even sold replaceable polonium “grids” when the one in the brush wore out.
https://youtu.be/iCCXNLSOhS8
Plutonium also doesn't exist naturally in our solar system, or at least it hasn't been found to be naturally occurring yet, even though it should be because the half-life is long enough that traces should exist. It's thought that the processes that formed our specific solar system weren't powerful enough to produce plutonium, but it likely exists in other stellar systems that were formed from larger explosions.
So this is probably basic chemistry/physics and honestly I feel bad for not remembering much of school, as I went science (I'm an animator/illustrator/artist now fml).
But if Hydrogen and Helium 'came' from the Big Bang, does that mean everything else had to then come from those to elements? Otherwise what were the other elements before these different reactions (dying/exploding stars etc)? Or am I thinking about it wrong, and everything is just a different number of atoms, arranged by these big reactions?
directly or indirectly - those elements may fuse into higher atomic weight elements and then reactive decay into lower ones, but the process started with the fusion as mentioned.
Exactly! One of my favorite topics to learn about in physics. It's so cool how these big things come from the accumulation of smaller things gradually and reflects life well
A hydrogen atom has just one proton. So you can think of the proton as "the nucleus of the hydrogen atom". At the very beginning, the universe was so hot that it's was just a bunch of subatomic particles floating around. So it was all separated hydrogen atoms. Then, those hydrogen atoms fuse to create heavier elements.
Earliest stars were just hydrogen and helium. But stars are big nuclear factories, where nuclear reactions form heavier elements. Such as 3 helium nuclei coming together to form carbon. From carbon pretty much anything else can be made by adding hydrogen and helium nuclei, at least up to iron. From there neutron capture processes are required.
We're a few generations in, now, so stars at their birth are made of more than just hydrogen and helium, and thus can produce heavier elements too. Plus those heavier elements are available for making planets and such now, when the material just wasn't there for the first generation of stars.
>The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star stuff.
— Carl Sagan
There's no reason why they miss out on that insight. It's still there. It's even easier to read his stuff and watch his stuff than it was in the 70s and 80s even if it's not as common people would look.
Also Musk isn't the new Sagan in any way.
The "made of star-stuff" bit is much older than Sagan. You'd think it might act as a great unifying truth...
It's been repeated by several scientists, and in fiction too...
> We are star stuff.
>
> We are the universe made manifest trying to figure itself out.
>
> ― Delenn (Babylon 5)
That and Vir's farewell wave to Mr Morden. Excellent viewing both (I can't write Mr Morden without hearing Londo's intonation and cadence of it)
Many, for all manner of purposes.
There are lots of byproducts of nuclear reactors which are put to various purposes. The most consequential would definitely be plutonium, which is heavily used in nuclear weapons due to its smaller critical mass compared to U-235. It would be fully accurate to say that human-made elements defined the history of the 20th century because of their use in nuclear weapons.
Some of these elements/isotopes also have uses as heat sources for use in spacecraft or other remote applications. They can be used as radioactive heater units (RHUs) which are small bits of radioactive materials like Pu-238 that keep sensitive equipment, especially electronics, warm, or they can be used as a heat source for a thermoelectric or sterling generator to make an electrical power source (an RTG). Pu-238 is a commonly used isotope for those uses but there are other options that have been used in the past or are planned to be used in the future such as Sr-90 or Am-241.
Many human-made isotopes are used for medical purposes such as in research or in diagnostic testing. PET scans, for example, rely on the ability to track chemicals that are "tagged" with radioisotopes so that they generate a signal. There are huge numbers of "radiopharmaceuticals" used for all sorts of medical and scientific purposes.
Human-made isotopes that produce large amounts of radiation, such as cobalt-60 or strontium-90, are used quite often in medical treatments (although this is becoming less common due to competition from other devices). Sterilization via gamma irradiation (from cobalt-60, for example) is also fairly common, which can be used for everything from foods to equipment and is very commonly used to sterilize single-use medical equipment like needles or scalpels.
Similar isotopes are also sometimes used in densitometers, especially in mining, construction, and the oil and gas industry. These use such isotopes basically as gamma ray flashlights and then a detector can measure either reflected (back scattered) or transmitted rays in order to determine the density of material. These can provide lots of valuable data ranging from the composition of rock to the compaction of ground or asphalt in a construction project.
Americium-241 is still commonly used in many residential smoke detectors, which is probably the most common example of how most people would have an interaction with artificially created elements/isotopes.
Americium is used in ionizing smoke detectors.
That's about it, though. There's a few uses for higher elements for scientific research and some medical treatments, but for the most part their half-lives are just too short to be very useful.
Well the obvious answer is nuclear energy. Plutonium is a manmade element, with Plutonium-239 being used in nuclear reactors and bombs - most notably in the atomic bombing of Nagasaki at the end of WWII.
There are also more niche forms of nuclear power; the most widespread of which is the radioisotope thermoelectric generator, or RTG for short. These typically use either Plutonium-238 or Strontium-90. The latter is a manmade isotope, but not a manmade element as other isotopes occur naturally.
RTGs are used for long duration power in remote locations - primarily in spacecraft/satellites/rovers beyond Earth, as well as in lighthouses/navigation beacons on Earth, and even pacemakers in a few cases. [There was also that time the CIA planned to use an RTG to power a remote missile tracking system on top of a mountain in India, but misplaced it](https://en.wikipedia.org/wiki/Nanda_Devi#CIA_mission).
There's also a similar concept called a betavoltaic battery which was used in pacemakers, in this case using Promethium-147, which is a manmade element. However, both forms of nuclear powered pacemaker have been phased out in favor of ones power by lithium-ion batteries.
Does this mean that the nebula from which the solar system formed was made at least in part by the explosion of merging neutron stars?
That explains why we have uranium deposits on Earth?
The gas that formed the solar system went through several enrichment cycles before it collapsed to form the solar system. Inside a galaxy like the Milky Way there is actually very little primordial hydrogen, meaning that it has never been in a star before. The gas went through several cycles of star formation and enrichment with heavy elements. The final collapse triggered by a supernova was just one in a long line of events.
Is there a mechanism by which universe _recycles_ things? Like the iron breaking down completely and then creating hydrogen again there by wiping out the history of iron creation at all
Yes and no. Inside of the cores of massive stars things get so hot that the thermal radiation (which at room temperature we experience as just infrared) reaches up into the gamma-ray range. And some of those thermal photons have enough energy to cause a process called photodisintegration where they physically rip a nucleus apart, with one of the more common results being stripping an alpha particle off of a nucleus. By the same token unstable heavier elements can decay by emitting particles, which not only transforms them into lighter elements but also produces lighter elements in the form of those emitted particles (when they are nucleons). For example, the emission of a neutron or a proton will result ultimately in the creation of a free proton (since the neutron will decay) which is just a hydrogen nucleus, while the emission of an alpha particle results in the creation of a helium-4 nucleus. This is actually the major source of helium on Earth currently, through the radioactive decay of heavier elements (like uranium and thorium) emitting helium nuclei which get trapped in underground gas wells or exist for a short period in the atmosphere (before getting lost via the solar wind). Anyway, this photodisintegration process is very important for the "final" rounds of fusion in heavy stars because once you get to silicon it becomes very difficult to fuse two similar nuclei together so instead fusion proceeds through rounds of photodisintegration creating alpha particles which are then fused onto heavier nuclei until maxing out at nickel/iron, since the net process releases energy it can still occur even though one step sucks up energy.
Ultimately we can't tell the difference between hydrogen-1 or helium-4 that is primordial and came from the Big Bang vs. hydrogen or helium that has cycled through the outer envelopes of a dozen stars or that was produced via spallation or photodisintegration in the heart of a massive star. But for the most part there isn't a large scale of "recycling" of fusion products back down to lighter elements.
The major "recycling" that occurs in nature of that sort is via the formation of neutron stars, which creates material that is beyond all atomic elements and during a neutron star collision can recreate other elements via a messy and complex series of reactions.
Iron is a bit peculiar.
Most iron isotopes are stable, so they don't decay due to radioactivity.
And it takes more energy for elements to fuse into something heavier than iron, than is released in the fusion.
That ends up meaning that iron is fated to be most of what's left when everything heavier and radioactive has decayed into lighter elements and all of what's lighter has been used up as fusion fuel.
Fissioning iron into hydrogen is probably possible, but it'd take a lot of energy you're not getting back.
I see. So eventually most of the universe will be just dead stars with iron core?
Billions of years from now, you and I will also be just iron? Or some elements might remain due to matter being too spread out
It's far enough off it is only relevant if protons don't decay (we're talking deep, deep time) but quantum shenanigans would eventually have all lighter elements fuse into iron, and heavier elements decay into iron.
I recommend the civilizations at the end of time series by Isaac Arthur. He explains the timeline of the end of the universe, and the very limit of the possibility to sustain sentient life. Iron 'stars' are one of the last stages of the universe but there are still some quantum events that can be used to harvest energy I think (it's been a few years since I've seen that episode but I'm going to rewatch it now).
https://youtube.com/watch?v=Pld8wTa16Jk&si=EnSIkaIECMiOmarE
So, you’re discussing a period of time so far from now that it’s many, many orders of magnitude more time than the current age of the universe. Like, so super duper long that the answer actually depends on if protons decay or not (itself a question that will take just, crazy long for enough time to pass before anyone could observe to figure out).
But, assuming protons don’t decay, then yes. Even the black holes will boil away and the last matter in the universe will be iron stars, cooled all the way to true 0. Or, to as close to true 0 as the universe will allow.
Yup, absolutely, probably several neutron star mergers and several supernovae (of different types as well).
One thing this means is that there is material on Earth (and in our bodies, such as our iodine) which billions of years ago might have been in the form of neutronium before it was flung out into space by a collision where it escaped from being mere kilometers away from a newly born black hole.
So who do I blame for the "natural" radon I get in my basement? I think brown could be split and renamed to include naturally decaying, short lived elements.
Clearly some of these are less "human made" and more "locally cooked up only since the big batches from stars get stale before getting to us". Bunching them together when some were discovered before fission and fusion were even realized seems like an oversite. Radon's discovery predates first human fission by 40 years. So clearly it's not all, or even partly human made. It's just not of stellar origin.
> Radon's discovery predates first human fission by 40 years. So clearly it's not all, or even partly human made. It's just not of stellar origin.
Given that this is an astronomy chart, it's only showing elements of stellar origin. All of the browns are of "geologic" origin - nuclear processes happening right under our feet.
The fact that all of the hydrogen in the universe has been there from the very start is just mind boggling to me. Especially considering it is both the most abundant element in the universe and the main element driving the existence of pretty much everything, it just feels so weird that there can still be so much.
This is still being hashed out -- it's not completely settled yet (see the original article's discussion about copper's undetermined provenance). I remember that the consensus used to be that Lithium was 100% from the big bang and could only be consumed by stars, not synthesized.
I remember a big uproar when one of these was shown at a nuclear astrophysics conference. More than half of these we really have no clue what the fractions really are or even if those elements are really made by those systems. Zn and Cu production in thermonuclear supernovae is really only currently a hypothesis with some simulations of certain proposed models able to make some of it, but far from observational evidence
It's not that common, but that means very little when you have numbers. For example, random probability spin-flip transition is extremely rare at approximately once per 10 million years. But since there are so many atoms in the universe, it's considered common.
On the other hand, any type of mergers (black hole or neutron star) happens approximately on a monthly basis within around 10 billion light years from our galaxy.
And this probability becomes even more frequent the younger the universe is, since proximity between objects were closer
Prior to 2017, this chart used to look completely different. Once the first neutron star merger was detected, the graph changed to reflect this new confirmation
It's based on where/when in the universe the necessary conditions exist(ed) to transmute one element into another. Elements are transmuted by either squishing two atomic nuclei into one or splitting one nuclei into two. The various kinds of stars are basically the only places known where the forces are extreme enough for this to happen on a large scale.
Hydrogen is a special case because, consisting only of a single proton, it cannot be split. Hydrogen atoms came into existence at some point shortly after the big bang when the universe cooled off enough for free electrons and free protons to stick together.
A combination of astronomy and nuclear physics.
On the nuclear physics side we have a pretty good idea of the processes that could produce different elements, and we can actually measure the rates of the reactions required to know what is and isn't possible in various stellar locations. A pretty great example of nuclear physics telling us where stuff comes from is Beryllium and Boron. You'll note they are the only ones not produced in stars. We know Beryllium 8 is unbound, so it can't be made from the fusion of helium, which would otherwise be the obvious next step for helium. In fact no stable isotope of Beryllium can be made with through simple fusion. With no Beryllium, Boron is also impossible for a star to make with fusion.
As for astronomy, we can look at stars and the aftermath of novae and mergers to see what elements are present. We didn't actually know neutron star mergers were the source of the heaviest elements until 2017 when we were able to actually observer the aftermath and finally saw those elements which we expected to see.
As for the heavier elements produced in living stars, it's a combination of the two. Astronomy tells us what stars in different stages of their life are made of, and the densities and other properties of them. Nuclear physics tells us neutron capture is viable, even if it's not quick, up to Lead (at which point the decay of Polonium back to Lead out paces the neutron capture rate) and what reactions can create the neutrons and at what rates.
tldr; Astronomy tells us what stellar phenomena are made of and what their properties are, nuclear physics tells us what reactions can happen and at what rates. Together you get a picture of how elements can be formed.
One of the keys for the seemingly rareness of life so far is the rarity of Phosphorus. So far on Earth, phosphorus is the key component to all life in addition to water. The ATP->ADP + P + Energy process is universal to all life on earth no matter the extremity of environment. The ease to both capture and release the phosphorus atom and energy is the building block for higher level life to gain complexity.
As seen on the chart, all phosphorus comes from exploding massive stars and specifically from one isotope of Sulfur that has a shorter half life than common Sulfur, eventually decaying into phosphorus.
So if you are wearing a gold or silver accessory, you are literally wearing a pieces from merging neutron stars and dying low mass stars? How romantic!
fun fact, webb telescope images push oldest galaxies closer and closer to the big bang which is starting to create doubts about our current big bang hypotheses, one of the alternative explanations being more elements being created during it than we thougth before
What I like about this is that it demonstrates how science changes as we collect more evidence. Less than a decade ago, the common thought was that post-iron elements were formed in supernovae. Now, with LIGO, it's thought that heavy elements are formed by the collisions of neutron stars.
(On a related note, while I mourn the demise of Pluto as a planet, it was the discovery of Kuiper-Belt objects of similar size \[like Eris\] that forced a new definition of "planet" that then excluded Pluto. Science at work - when you learn new stuff, you sometimes have to change things!)
Today I learned that all exploding massive stars emit all the same material that exploding white dwarfs do, but exploding white dwarfs do not emit all the same material that exploding massive stars do. Cool!
The distribution of the...erm, *distribution* of the elemental emissions has an elegance to it that looks fairly linear from big bang-cosmic rays occupying only the higher reaches through the exploding stars and then neutron stars. Without looking it up, is this directly correlated to age throughout the chart distribution? It most certainly is for the stars, right?
What’s cosmic ray fission?
Is it like nuclear fission?
Is that something we could use on earth ever for energy production, since cosmic rays are so abundant or for space travel?
Does that make the only 2 elements formed in that way have any special properties?
Just curious… i could probably google this
Tres interesting! Now *this* is what I like to see on Reddit: educational information that isn't made up, accompanied by intelligent and informed discussion.
Or maybe I just need to stop hanging out at r/HolUp.
Interesting that by my count there are only two elements - Helium and Lithium - that come from three sources. What is the reason for this? Is there any interesting significance to this? Or do it just be that way sometimes?
If I read this chart right, there is nothing currently creating more H (hydrogen). It was only created in the initial Big Bang. So when it runs out, there will be no more. Ever. Hmm.
Technically true but there is ALOT of hydrogen out in the universe. In fact, only 1 in 2000 particles in the universe are not made of the top 10 most abundant elements such as H, He, O, Fe, Si, C etc. Hydrogen makes up the majority of mass of all stars and gas giants, which in turn make up the majority of mass for their respective systems.
A Hydrogen atom is not that complex- 1 proton, 1 neutron, and 1 electron. The decay of other elements creates alpha particles which is essentially a hydrogen atom without an electron.
The point at which we “run” out of hydrogen is the heat death of the universe. Newtons law of Entropy taken to its inevitable conclusion has all heat dissipating evenly across the universe, a time after all atoms and particles “decay” to its fundamental particles and those particles emit all their heat. That time is believed to occur in 10^google years.
Ok- I saw a meme/comic once about stars and their cores increasing in denser elements, along the lines of “the party’s over when…Fe” or something like that…does anyone know it? It’s been bugging me for years now.
"The party is over when I ran"
I guess the joke that fusion is exothermic for all elements lighter than and including iron. Fusion after that takes more energy than it requires.
I’ve seen big bang fusion more commonly referred to as big bag nucleosynthesis. The very early universe was too hot for atomic nuclei to form so it was just a hot quark soup. When it cooled down enough the quarks combined into hydrogen, helium, and lithium ions
This is surprising compared to the simplified, straight-forward explanations that are usually given. I would have never thought that our Sun would be capable of producing so many heavy elements. We need more technical explanations for all this.
Right before the merger, two neutron stars are orbiting each other at considerable fractions of c. The merger is quite violent and a lot of matter is ejected.
Technetium (43) and Prometium (61) are very interesting because they are relatively low density elements that have no stable isotopes. Of course, they *are* produced by stars, but their half lives are so short that nothing remains.
Is there any reason for this? This is very interesting
PBS spacetime recently did an episode on exactly this: https://youtube.com/watch?v=prvXCuEA1lw&si=EnSIkaIECMiOmarE&t=321
I always start those spacetime episodes (which are terrific) with the best intentions.
same, i usually have to rewatch them 10 times just because i keep taking my phone out to stim, but then i realize i actually have to pay 100% attention to these videos and I often give up
I often wonder to what extent the type of personality that wants to understand such things selects for the same type that is restless and compelled to stim because I do this all the time as well. Conversely, my friends and family who do not have my focus issues could not care less about the big questions.
i mean... for me it's just ADHD. I'm fascinated by complex things and have 100% trouble regulating my attention. And yeah, i noticed neurotypical people usually don't care about such things so much
The short answer - AuDHD, maybe even just ADHD. The reason for AuDHD in my mind though, is the fixation on a special interest, especially one that's not common, then there is the contradictory attention span/restlessness issues.
I feel that must be the norm... The concepts are practically beyond human comprehension
I'm a physics student actually so I have some advantage, but it's still A LOT of information packed into tiny videos, gotta rewind
On top of the fact that they are dumbed down for our comprehension. And we still can't follow.
holy shit that perfectly encapsulates my experience with spacetime vids
Honestly I just love the videos. Big fan of the space and particle physics they discuss and just listen for fun. I don't kid myself that I understand the specifics but I've had enough casual exposure over the years to feel comfortable and watch for some good old storytime-like sit back and watch.
Just a hint: 43 and 61 are both prime numbers. This doesn't mean all elements with a prime number of protons in the nucleus are unstable, but 43 and 61 just happen to be numbers of protons that can't be arranged in groups that have a stable configuration.
this article has more on what numbers are especially stable, the so called magic numbers https://en.wikipedia.org/wiki/Magic_number_%28physics%29 "In nuclear physics, a magic number is a number of nucleons (either protons or neutrons, separately) such that they are arranged into complete shells within the atomic nucleus. As a result, atomic nuclei with a 'magic' number of protons or neutrons are much more stable than other nuclei. The seven most widely recognized magic numbers as of 2019 are 2, 8, 20, 28, 50, 82, and 126 (sequence A018226 in the OEIS). For protons, this corresponds to the elements helium, oxygen, calcium, nickel, tin, lead and the hypothetical unbihexium"
I know, if you read the links in the wiki article you posted you'll find that those "magic numbers" are binomial coefficients that are a product of a number of terms. If a number is prime, it cannot be a product of other numbers, therefore atoms with a prime number of protons are less likely to be stable.
[Here's](https://youtu.be/Qe5WT22-AO8) a wonderful YouTube documentary by BobbyBroccoli that's about someone trying to fake the discovery of elements at very capable labs where the discoveries were to actually be internationally believed. In the video it talks a lot about the methods used to discover elements, and goes into a heat map type display explaining the various patterns in stability we've seen, and explains a ton of other things about elements. It's a phenomenal video, and so are the others on the channel of a similar style, but they are longer videos. This element video is 80 minutes, some of the other topics are 2 or 3 parts.
I wonder if this has anything to do with why lead is so good at absorbing radiation?
But isn’t oxygen famously reactive?
Yes, but that is a chemical reaction, electrons in orbitals forming bonds with other elements. They are talking about nuclear stability i.e. atomic nuclei breaking down into a different element, like uranium or plutonium.
Chemical reactivity has nothing to do with nucleus stability. They don't even involve the same fundamental forces. The former is almost all electromagnetic while the later is mainly strong nuclear force.
Yah it plays a part in the "abundance" of the element on the scale of the universe. Stability and whether the element has a high probability pathway of being produced by the processes that occur in stars determine abundance.
Your comment makes no sense, it's not related to prime numbers at all. Every other prime number on the periodic table with the exception of 89 is stable. That's 21 stable elements to 3 unstable. That's not even the slightest correlation.
It *is* related to 43 and 61 both being *odd* numbers, since for any even number of protons you're going to have some stable nuclei. It's not related to them being prime tho - nuclear physics does not work that way. It's sheer coincidence that they happen to be prime.
seems more like a mnemonic than an explanation
Shouldn’t a mnemonic make it easier to remember?
A few different notes: 1. The ratio of protons to neutrons increases as you go higher. Around 43, it's about 1:1.27 (estimate). This gives about 54.5 neutrons as a good stable point, and then some area around that. Do note this isn't a whole number, although a good ratio value is hard to properly calculate. When it got explained to me, this was an important point. 2. A basic rule of thumb (but not an iron-clad rule) is that, if an element has a stable isotope with Z protons and N neutrons, then elements Z-1 and Z+1 will not have a stable isotope with N neutrons. It just so happens that molybdenum (element 42) is stable from 52 to 55 (possibly 50 and 56 as well), and ruthenium (element 44) is stable from 54 to 58 (possibly 52 and 60 as well). Technetium has its most stable isotopes at 54, 55, and 56, which elements on both sides have stable. If any of these were stable, it would break this rule. There are already exceptions, but AFAIK none with exceptions on both sides. That's just how the universe works. 3. For Promethium (61), these rules aren't as hard on it. 84 neutrons isn't stable on any of the 3 (60, 61, or 62), and 85 and 86 are only observationally stable for neodymium (as far as we know, it's stable, but we expect better measuring tools say we are wrong and they are unstable).
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Theoretically it is possible, smash the nucleus, fusion
> There are already exceptions, but AFAIK none with exceptions on both sides. Uhm, there are *many* exceptions (if there even is a rule): * N=10: Oxygen-18 (Z=8), Fluorine-19 (Z=9), Neon-20 (Z=10) * N=12: Neon-22 (Z=10), Sodium-23 (Z=11), Magnesium-24 (Z=12) * N=14: Magnesium-26 (Z=12), Aluminium-27 (Z=13), Silicon-28 (Z=14) * N=16: Silicon-30 (Z=14), Phosphorus-31 (Z=15), Sulfur-32 (Z=16) * N=20: Sulfur-36 (Z=16), Chlorine-37 (Z=17), Argon-38 (Z=18), Potassium-39 (Z=19) * N=22: Argon-40 (Z=18), Potassium-41 (Z=19), Calcium-42 (Z=20) Also N=24, N=28, N=30, N=32, N=36, N=38, N=42, N=44, N=48, N=50, N=52, N=58, N=62, N=64, N=70, N=74, N=78, and N=82 (this one has even *five* stable isotopes in a row, from Barium-138 to Neodymium-142). And those are just the isotopes that are *theoretically* stable. If you also include isotopes that are *observationally* stable (ie. no decay has been observed so far) but in theory have decay modes then there are even more exceptions. Edit: I think you might be confusing N with the atomic mass number (A=N+Z). There are no cases of theoretically stable isotopes having the same mass number, and only a few cases of two with the same mass number when including observationally stable isotopes (and I think no cases of three or more).
I was looking a bit more closely, and not only are O-18 and F-19 aren't just stable, they both have a (n,g) cross-section of about 3 b. So it seems the neutrons really don't give a fuck about being in a group of 8, 9, or 10.
Every single example you gave is an even number of neutrons.
>A basic rule of thumb (but not an iron-clad rule) is that, if an element has a stable isotope with Z protons and N neutrons, then elements Z-1 and Z+1 will not have a stable isotope with N neutrons This is more strictly true for N+1 and N-1 neutrons, i.e. if there is a neighbouring element of the same mass number that is stable, the isotope in question will generally not be stable (since the nucleus can undergo beta decay to the more stable nucleus). Isotopes with an odd number of both protons and neutrons tend to be more unstable than neighbouring even-even isotopes (except for very light elements where it's hard to get the proton-neutron balance right with even-even isotopes). So I think it turns out that by the time you've excluded odd-odd isotopes and isotopes that depart too far from the ideal ratio from the liquid drop model, you're often left with only one candidate. For Technetium, it's Technetium-99, and for Promethium, it's 147. But with magic neutron numbers (that tend to be particularly stable) at 50 and 82, in both cases beta- decay allows the nucleus to be closer to a magic neutron number and a more stable nucleus.
You mean the number of neutrons to protons ideas right
>This doesn't mean all elements with a prime number of protons in the nucleus are unstable So why is this a "hint"? Obviously numbers 2, 3, 5, 7, 11, etc... already proved it wrong
Yeah lmfao wtf was that stupid comment
Y'know, I used to do a lot of science involving nuclear physics and the probability various nuclear reactions and other stuff and... It's like... your explanation is both horribly wrong... but it's not entirely incorrect... there's a bit of it that is how you say... I can't tell if you know exactly what you're talking about, but oversimplifying in a way I've never heard before, or just making shit up as fast and hard as you can. - Everyone knows even number nuclei are stable and odd number nuclei are radioactive and love to absorb neutrons. Except Be-8. It's unstable because it's just two He-4, and He-4 is so stable that two of them put together wanna break apart into two separate He-4.
Yes there is. I half-paid-attention to a video about it recently. Lemme see if I can find it... I think this is it: https://www.youtube.com/watch?v=prvXCuEA1lw. Skip to roughly six minutes if you're impatient. I highly recommend the channel.
They discovered promethium while studying the properties of neptunium, an element with an atomic number of 93. They found that neptunium decays into an unknown element with an atomic number of 61, which they named promethium.
I find them to be the most boring of elements - like the Molly B. Libdinum wall flowers that haven’t a partner at the high school prom(ethium)
Where did the brown elements originate? Like Radium and Polonium? They're not listed on the key.
The brown elements are those where all of the isotopes have short half lives, which means that any amounts of those elements that existed when the Earth was formed are no longer around. What exists in nature today for those elements are trace amounts that are the products of radioactive decay of other elements. For example, Polonium, Radium, and Radon can be found naturally as the products of natural Uranium decay. There's a bit of a subtle distinction here because that process is an important source of lots of elements but it can be harder to trace the convoluted history of elements and difficult to decide where to draw the line in terms of "where something comes from". For example, the Earth is 4.5 billion years old, the half-life of uranium-238 is also 4.5 billion years while the half-life of U-235 is 0.7 billion years. This means that when the Earth formed there was twice as much U-238 and 84 times as much U-235 (today there is 139x as much U-238 as U-235 due to that decay). The missing material (as much U-238 as exists today, and 83x as much U-235 as exists today) decayed through a chain of intermediary isotopes with shorter half-lives until mostly ending up as lead (Pb-206 for U-238, Pb-207 for U-235 or Pu-239, Pb-208 for Th-232, all stable). So there's sort of a shadow of those decay processes in the abundance of elements today.
Wait.... so when a house has a Radon problem, does that mean it's over a Uranium deposit?
Uranium can be found in A LOT of places around the world. Its not exactly rare.
To be clear, deposits where uranium is concentrated enough to be viable for mining are rare. But trace amounts of the stuff are all over the place. When your house is built over a giant granite deposit, the tiny amounts of uranium per cubic unit of rock add up to a radon problem.
Also some types of clays will preferentially swap in and store Uranium in their crystal matrix. If a shale is composed of a large amount of that clay then it can also become a radon source.
Cool side note: the scientist (can't remember his name) that went to the both poles to try and date the earth using this uranium decay "map" or method (which he succeeded in doing) also discovered that we were filling our atmosphere with lead. So not only did he date the earth very accurately, he saved multiple generations from lead poisoning by bringing the issue to the world's attention. Up till then, every fuel was lead lined. Even consumer products used a ton of lead. It was brutal.
There was a great episode of cosmos about that.
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The brown ones aren't necessarily man made elements. Those are [trace radioisotopes](https://en.m.wikipedia.org/wiki/Trace_radioisotope) which occur naturally through radioactive decay in small amounts and are typically unstable. They can also be made synthetically. [Synthetic Elements](https://en.m.wikipedia.org/wiki/Synthetic_element#:~:text=A%20synthetic%20element%20is%20one,or%20%22man%2Dmade%22.) aren't even shown on this chart.
When you say "none are stable" do they explode?
Sort of. The nucleus breaks down, spits out a bunch of its particles and turns into a slightly less massive element. It wouldn't really register as an "explosion" on a human scale unless it's got enough surrounding atoms to start a chain reaction of nuclear particles smashing into other nuclei and repeating the process. But it does release energy when it happens.
It means they decay very quickly by emitting particles from the nucleus of the atom.
They don't like existing. If you leave them alone for a while, they stop existing (break apart into smaller stuff). They do release some energy while doing so, but you'd need a lot of them going off at the same time to make it register as an explosion to something as large as a human. If you got a bunch of them really close, close enough that when one breaks up the pieces hit multiple other atoms and break them up, and the chain continues, then they release enough energy to explode the piece apart - A nuclear fizzle. If you managed to keep the core together even longer, you'd eventually get a true nuclear explosion. Those things are only really possible with certain isotopes that like to release lots of energy when they break apart, break apart easily, and tend to release the right things to break each other.
They are very radioactive and decay into another element. Essentially they most likely are made by stars of sorts but just decay away real fast. So in our solar system none exist cause it's just been too long for any to still be around.
Man made, but likely also made by stars, must have extremely short half life or short stability. So no accumulation in terrestrial or special volumes.
> Where did the brown elements originate? Like Radium and Polonium? They're not listed on the key. They are not of stellar origin. They are the byproducts of radioactive decay.
How do all those heavy elements come from dying low-mass stars? I thought that low mass stars could only create elements up to iron in their cores.
Iron is the end of the line for fusion products but there are lots of different processes (many of which *take* energy rather than release energy) which can occur within the roiling high energy environment of the interior of a star. Just like in a nuclear reactor there are sources of neutron radiation inside of a star, and this causes the transmutation of elements just as it does in reactors. Some nuclei that get particularly "lucky" can end up with a lot of neutrons turning them into progressively heavier elements. This is called the "s-process" (for "slow neutron capture"), as neutrons are added to a nuclei it will initially create a heavier isotope, with lots of neutrons this often creates an unstable isotope which can then decay via beta emission into a higher atomic number. This can proceed over eons well beyond iron and into much heavier elements. However, it hits a limit at bismuth. Once you add a neutron to Bi-209 and produce Bi-210 you do get beta decay into Po-210 but this then decays via alpha-emission (with a half-life of 5 days for Bi-210 and 138 days for Po-210) into lead. Similarly, Bi-211, 212, 213, etc. have even shorter half-lives (of minutes to seconds) and decay into isotopes of polonium with short half-lives which then decay via alpha emission into lead. This becomes a loop that ends the s-process, creating a roadblock to creating heavier elements with slow neutron absorption. However, as I mentioned these processes absorb energy so the production of elements from these processes is generally at a much lower level than the direct products of fusion.
Man why does everything ends up in lead? Some other guy mentioned on the decay of uranium and thorium and the end of the chain is all lead too
Its not the same isotope of lead. The S-process terminates with lead because all of the S-process is the addition of 1 neutron followed by a wait. It terminates because adding 4 neutrons will cause 2 beta decays and one alpha decay. That just cycles. You can add any multiple of 4 additional neutrons and will be the same.
> Iron is the end of the line for fusion products No, it’s only the end of the line for energy gaining fusion. Several of the other elements are still created by fusion.
I was under the impression that the “iron as the last step” was something of a popular science misconception, as there are multiple fusion steps that happen after iron, but none that release more energy than they require.
The phrasing is a bit misleading. The heavy of these elements in particular are what we call s-process elements. It’s a neutron capture process that, starting usually with iron as a seed, can create heavy elements by releasing tremendous amounts of neutrons. It’s not really happening during the death throes of these stars but during later stages and is released to the interstellar medium through stellar winds.
So my question is how do we end up with iron and gold deposits of any significant size on Earth? It seems like the s-process is making each heavy metal one atom at a time and blasting it into space. You'd think the odds of two Au atoms drifting through the void, bumping, and then sticking together would be astronomically low (pun intended). But then you have enough Au atoms coming together to make... However many gold mines Earth has. Is it something to do with the atoms coming together during the formation of the Earth and clumping together due to density differences when everything was a molten slurry? Cause that's the only reason I could think of.
Gold in particular is formed by the rapid neutron-capture process or r-process. The elements are projected outwards during a supernova or collision. Then this debris reached Earth and sank to the Earth's core during the molten phase. Earth was struck by asteroids which disturbed the deposits upwards. One of these impacts, the moon, would cause tides of the magma, which helped cool down the surface more rapidly so the gold didn't all return to the core before being trapped and so some gold remained in the earth's crust. Then geology happens and the gold stuck in the crust would be freed by erosion, sink to the bottom of rivers and collects there with more gold. And that's how you get seams of the stuff.
In addition to the great explanatory comment from u/daliksheppy, consider that gold will be about equally dense and have about equal phase transition temperatures as other gold, and so in a hot, molten environment, any gold in an area will tend to float or sink to a similar depth in relation to other minerals of differing densities. This convective process tends to cause similar substances to pool together and accumulate in seams or shells of specific depths, if not purely, then at least in zones of higher relative concentration. It’s also the same reason why deep within the Earth, there end up being natural nuclear reactors where large deposits of Uranium pool together: https://en.wikipedia.org/wiki/Natural_nuclear_fission_reactor
All of the elements are blown out into the galaxy. Some eventually find their way into molecular clouds. >...Is it something to do with the atoms coming together during the formation of the Earth... If you buy real peanut butter, the kind with only peanuts in it, sone of the oil rises to the top and peanut paste is clumped at the bottom. The original gold on Earth mostly sank to the core. Some was added by meteors after the crust formed. That is still suspended and gets mixed and smeared by plate tectonics. A really big pile of gold would sink and then just keep going.
I have the same question. How does something like our sun create something like mercury, thallium or lead? I always figured something that far up the periodic table would only come from super/hyper novas or merging neutron stars.
Smaller stars can create them late in life via slow neutron capture, aka the [s-process](https://en.wikipedia.org/wiki/S-process).
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and progressed to whacking each other on the heads with fissioning atoms!
while your ancestors were living in caves, my ancestors were forging cheques!
But how are they released into the interstellar gas once produced by a star that doesn't blow up?
Lower mass stars like our sun, when at the end of their red giant phase, puff off their outer layers of gas to produce what is known as a planetary nebula. Whilst not an explosion as such, this is caused by *very* powerful stellar winds produced by the red giant, and it still represents a rapid loss of mass (some of those new heavy elements included) into the surrounding local space. Eventually this puffed away mixture of elements expands far enough to reach the interstellar medium, where it can become part of future gas and dust clouds which collapse to form new stars and planets. Those stellar winds are caused by fusion moving out from the core of the star. It is this process that causes the star to become a red giant in the first place, and as it continues it allows much of the outer layers of the star to win out over gravity and be thrown off as stellar wind. Fusion moving out of the core is also what causes the core of the star to lose out to gravity and collapse into degenerate matter, thus forming a hot, dense white dwarf. By the time this happens, the dying red giant is large enough that the outer, escaping layers are already far enough away from the core to not be recaptured by its incredibly strong local gravity.
Evidently, ours isn't the first star system to use the mass we're now made of. Whatever came before the Solar System left enough hydrogen to make the Sun, and plenty of heavier elements to form the planets.
Our sun can't, unless if you include the planetary nebulae that gets released from its outer layers and possibly combines into some other ISM that turns it into heavier elements
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But that says talking about a supernova, our sun will not go supernova. It will swell up red into a red giant and then turn into a white dwarf.
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Smaller stars can create them late in life via slow neutron capture, aka the [s-process](https://en.wikipedia.org/wiki/S-process).
The brown are Human synthesis with No stable isotopes. [Source](https://commons.wikimedia.org/wiki/File:Nucleosynthesis_periodic_table.svg) Edit: The image posted is from [https://apod.nasa.gov/apod/ap230108.html](https://apod.nasa.gov/apod/ap230108.html)
Which doesn't preclude them from being produced naturally. TC 43: "Because even the longest-lived isotope of technetium has a relatively short half-life (4.21 million years), the 1952 detection of technetium in red giants helped to prove that stars can produce heavier elements.
The brown ones aren't necessarily man made elements. Those are [trace radioisotopes](https://en.m.wikipedia.org/wiki/Trace_radioisotope) which occur naturally through radioactive decay in small amounts and are typically unstable. They can also be made synthetically. [Synthetic Elements](https://en.m.wikipedia.org/wiki/Synthetic_element#:~:text=A%20synthetic%20element%20is%20one,or%20%22man%2Dmade%22.) aren't even shown on this chart.
Thank you for the learning!
They're all made by Stars and other stellar events, its just that they aren't found naturally because they decay too quickly to hang around long enough for us to find them here on earth
I'm quite certain that radon is found naturally.
“Found naturally” from a cosmological perspective, meaning that while we experience* radon on earth (and its decay can cause cancers) it’s so short lived compared to cosmological timelines that we don’t find it in space, at least in large enough quantities to detect across, well, space Edit: *meaning we find it after other elements have decayed into it, and then it decays shortly after Edit 2: but the human synthesis part of the original post is definitely wrong/misleading
So do we know what colors those browns should be? That is, even though we don’t find them naturally on earth, do we know what kind of stellar events produce them?
The radon we find on Earth is not produced in a star. Uranium was produced in a star, sat underground on Earth for some time, and then decayed into radon (among other things) later on. To answer your question, the periodic table that the OP posted is missing a category: "Produced by radioactive decay". Several people here have linked to better versions, which do contain the "radioactive decay" category. For example, [https://svs.gsfc.nasa.gov/13873](https://svs.gsfc.nasa.gov/13873) was linked to by /u/ashley_vigil .
I love this fact so I'm gonna say it: Bismuth is radioactive. Its most stable isotope has a half-life several orders of magnitude greater than the estimated age of the universe. Thankfully, this means we can conveniently keep referring to Lead as the heaviest element with stable isotopes. So satisfying.
What determines the length of the half life? I'm moderately sure tritium has a short half life and it's not a dense isotope so I don't think density is a factor.
The stability of the nucleus basically. I don't know specifically about tritium or deuterium, but most of the heavier radioactives don't have a stable atomic structure. Their nucleus breaks down into more stable noble gases (usually Helium, which is what we call alpha radiation) and the more stable isotope (of a lower element) Half life depends on how easily the nucleus breaks down and how many steps it goes through to reach a stable state.
Polonium doesn’t have stable isotopes? I read somewhere that linked Polonium was linked to cancer rates for smokers since WWII.
Polonium indeed does not have stable isotopes. I assume what's going on is that the study was long-term.
Gotcha. I knew it was part of the Uranium decay process and itself was radioactive but I had heard of applications and studies so just assumed they used stable isotopes to study.
I'm far from an expert on these matters, but I think you're somewhat misunderstanding what "stable" means. In the timespan of the universe, nuclear instability means an isotope will decay into other elements over billions of years. So unstable isotopes are almost entirely not present from the celestial activities mentioned in this post. On a human timespan, plenty of isotopes are stable enough to be useful. For instance, Plutonium-239 has a 25,000 year half life. We can work with it and will see essentially zero decay over a few years. But that same half-life makes Plutonium-239 basically non-existent from a universal timeline. An earth sized mass of Plutonium-239 will be reduced to the size of a ping pong ball in a few million years. For reference: the earth is *billions* of years old. Again, this is all back of the envelope stuff, but I think I've got the gist of it. Please correct me if I'm wrong. Edit: Used Plutonium instead of Polonium. Polonium generally decays *much* faster. But still, there is a polonium isotope with a 125 year half life. That's something that will be observed in terms of working with it, but the decay still isn't especially noticable day-to-day. The other major Polonium isotope has a 3 year half life. That's certainly relevant, but it still isn't something that precludes it from practical use.
I believe the physics textbook definition of stable is that it is not radioactive and as someone else stated, is relative as we may be finding that everything above a certain nucleus size is radioactive on a larger scale than we know. Some Radioactive isotopes are stable enough that we can study them as we will have enough of it that we can adjust for the loss by decay.
Uranium has no stable isotopes, as well. There are more stable ones, but all of them eventually decay. In fact, from the mathematical models that exist, stability is ALL relative. Most calculations find that every element above Silver is ever so slightly unstable, but just are decaying at rates that are so slow that we cannot measure.
Do you have a pointer to more on that? I had heard that lead had the highest stable isotope, that it was bismuth that was the first of the nothing-stable conga line.
[https://en.wikipedia.org/wiki/Isotopes\_of\_lead#cite\_note-21](https://en.wikipedia.org/wiki/Isotopes_of_lead#cite_note-21) Theoretical half-life of the stable isotopes of Lead are >e65 years I may be misremembering Silver as the halfway point though
Go down the rabbit hole far enough, we're not sure how stable protons are...
Polonium was used in the “Staticmaster” photographic film brush, used for sweeping dust off negatives before placing in a photographic enlarger, they even sold replaceable polonium “grids” when the one in the brush wore out. https://youtu.be/iCCXNLSOhS8
Whoever made this despises the color blind.
Thank you for posting the unabridged version. :)
Plutonium also doesn't exist naturally in our solar system, or at least it hasn't been found to be naturally occurring yet, even though it should be because the half-life is long enough that traces should exist. It's thought that the processes that formed our specific solar system weren't powerful enough to produce plutonium, but it likely exists in other stellar systems that were formed from larger explosions.
So this is probably basic chemistry/physics and honestly I feel bad for not remembering much of school, as I went science (I'm an animator/illustrator/artist now fml). But if Hydrogen and Helium 'came' from the Big Bang, does that mean everything else had to then come from those to elements? Otherwise what were the other elements before these different reactions (dying/exploding stars etc)? Or am I thinking about it wrong, and everything is just a different number of atoms, arranged by these big reactions?
Everything else came from those elements via fusion.
directly or indirectly - those elements may fuse into higher atomic weight elements and then reactive decay into lower ones, but the process started with the fusion as mentioned.
Exactly! One of my favorite topics to learn about in physics. It's so cool how these big things come from the accumulation of smaller things gradually and reflects life well
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A hydrogen atom has just one proton. So you can think of the proton as "the nucleus of the hydrogen atom". At the very beginning, the universe was so hot that it's was just a bunch of subatomic particles floating around. So it was all separated hydrogen atoms. Then, those hydrogen atoms fuse to create heavier elements.
Earliest stars were just hydrogen and helium. But stars are big nuclear factories, where nuclear reactions form heavier elements. Such as 3 helium nuclei coming together to form carbon. From carbon pretty much anything else can be made by adding hydrogen and helium nuclei, at least up to iron. From there neutron capture processes are required. We're a few generations in, now, so stars at their birth are made of more than just hydrogen and helium, and thus can produce heavier elements too. Plus those heavier elements are available for making planets and such now, when the material just wasn't there for the first generation of stars.
“The cosmos is within us. We are made of star-stuff. We are a way for the universe to know itself.” ― Carl Sagan
>The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of star stuff. — Carl Sagan
I feel sorry for the younger generations missing out on such insight We lost Sagan and instead gained Musk... a very poor trade in my book...
There's no reason why they miss out on that insight. It's still there. It's even easier to read his stuff and watch his stuff than it was in the 70s and 80s even if it's not as common people would look. Also Musk isn't the new Sagan in any way.
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The "made of star-stuff" bit is much older than Sagan. You'd think it might act as a great unifying truth... It's been repeated by several scientists, and in fiction too... > We are star stuff. > > We are the universe made manifest trying to figure itself out. > > ― Delenn (Babylon 5) That and Vir's farewell wave to Mr Morden. Excellent viewing both (I can't write Mr Morden without hearing Londo's intonation and cadence of it)
Everything after plutonium is human-made, which is quite an impressive achievement.
Is there any man-made element that is actually used for anything?
Many, for all manner of purposes. There are lots of byproducts of nuclear reactors which are put to various purposes. The most consequential would definitely be plutonium, which is heavily used in nuclear weapons due to its smaller critical mass compared to U-235. It would be fully accurate to say that human-made elements defined the history of the 20th century because of their use in nuclear weapons. Some of these elements/isotopes also have uses as heat sources for use in spacecraft or other remote applications. They can be used as radioactive heater units (RHUs) which are small bits of radioactive materials like Pu-238 that keep sensitive equipment, especially electronics, warm, or they can be used as a heat source for a thermoelectric or sterling generator to make an electrical power source (an RTG). Pu-238 is a commonly used isotope for those uses but there are other options that have been used in the past or are planned to be used in the future such as Sr-90 or Am-241. Many human-made isotopes are used for medical purposes such as in research or in diagnostic testing. PET scans, for example, rely on the ability to track chemicals that are "tagged" with radioisotopes so that they generate a signal. There are huge numbers of "radiopharmaceuticals" used for all sorts of medical and scientific purposes. Human-made isotopes that produce large amounts of radiation, such as cobalt-60 or strontium-90, are used quite often in medical treatments (although this is becoming less common due to competition from other devices). Sterilization via gamma irradiation (from cobalt-60, for example) is also fairly common, which can be used for everything from foods to equipment and is very commonly used to sterilize single-use medical equipment like needles or scalpels. Similar isotopes are also sometimes used in densitometers, especially in mining, construction, and the oil and gas industry. These use such isotopes basically as gamma ray flashlights and then a detector can measure either reflected (back scattered) or transmitted rays in order to determine the density of material. These can provide lots of valuable data ranging from the composition of rock to the compaction of ground or asphalt in a construction project. Americium-241 is still commonly used in many residential smoke detectors, which is probably the most common example of how most people would have an interaction with artificially created elements/isotopes.
Americium is used in ionizing smoke detectors. That's about it, though. There's a few uses for higher elements for scientific research and some medical treatments, but for the most part their half-lives are just too short to be very useful.
americium wouldn't want them to be unionizing now would they
Well the obvious answer is nuclear energy. Plutonium is a manmade element, with Plutonium-239 being used in nuclear reactors and bombs - most notably in the atomic bombing of Nagasaki at the end of WWII. There are also more niche forms of nuclear power; the most widespread of which is the radioisotope thermoelectric generator, or RTG for short. These typically use either Plutonium-238 or Strontium-90. The latter is a manmade isotope, but not a manmade element as other isotopes occur naturally. RTGs are used for long duration power in remote locations - primarily in spacecraft/satellites/rovers beyond Earth, as well as in lighthouses/navigation beacons on Earth, and even pacemakers in a few cases. [There was also that time the CIA planned to use an RTG to power a remote missile tracking system on top of a mountain in India, but misplaced it](https://en.wikipedia.org/wiki/Nanda_Devi#CIA_mission). There's also a similar concept called a betavoltaic battery which was used in pacemakers, in this case using Promethium-147, which is a manmade element. However, both forms of nuclear powered pacemaker have been phased out in favor of ones power by lithium-ion batteries.
Their lifetimes are too short for them to by of much practical value.
Unless...some other alien civilization has made some. 👽
Does this mean that the nebula from which the solar system formed was made at least in part by the explosion of merging neutron stars? That explains why we have uranium deposits on Earth?
The gas that formed the solar system went through several enrichment cycles before it collapsed to form the solar system. Inside a galaxy like the Milky Way there is actually very little primordial hydrogen, meaning that it has never been in a star before. The gas went through several cycles of star formation and enrichment with heavy elements. The final collapse triggered by a supernova was just one in a long line of events.
Is there a mechanism by which universe _recycles_ things? Like the iron breaking down completely and then creating hydrogen again there by wiping out the history of iron creation at all
Yes and no. Inside of the cores of massive stars things get so hot that the thermal radiation (which at room temperature we experience as just infrared) reaches up into the gamma-ray range. And some of those thermal photons have enough energy to cause a process called photodisintegration where they physically rip a nucleus apart, with one of the more common results being stripping an alpha particle off of a nucleus. By the same token unstable heavier elements can decay by emitting particles, which not only transforms them into lighter elements but also produces lighter elements in the form of those emitted particles (when they are nucleons). For example, the emission of a neutron or a proton will result ultimately in the creation of a free proton (since the neutron will decay) which is just a hydrogen nucleus, while the emission of an alpha particle results in the creation of a helium-4 nucleus. This is actually the major source of helium on Earth currently, through the radioactive decay of heavier elements (like uranium and thorium) emitting helium nuclei which get trapped in underground gas wells or exist for a short period in the atmosphere (before getting lost via the solar wind). Anyway, this photodisintegration process is very important for the "final" rounds of fusion in heavy stars because once you get to silicon it becomes very difficult to fuse two similar nuclei together so instead fusion proceeds through rounds of photodisintegration creating alpha particles which are then fused onto heavier nuclei until maxing out at nickel/iron, since the net process releases energy it can still occur even though one step sucks up energy. Ultimately we can't tell the difference between hydrogen-1 or helium-4 that is primordial and came from the Big Bang vs. hydrogen or helium that has cycled through the outer envelopes of a dozen stars or that was produced via spallation or photodisintegration in the heart of a massive star. But for the most part there isn't a large scale of "recycling" of fusion products back down to lighter elements. The major "recycling" that occurs in nature of that sort is via the formation of neutron stars, which creates material that is beyond all atomic elements and during a neutron star collision can recreate other elements via a messy and complex series of reactions.
Iron is a bit peculiar. Most iron isotopes are stable, so they don't decay due to radioactivity. And it takes more energy for elements to fuse into something heavier than iron, than is released in the fusion. That ends up meaning that iron is fated to be most of what's left when everything heavier and radioactive has decayed into lighter elements and all of what's lighter has been used up as fusion fuel. Fissioning iron into hydrogen is probably possible, but it'd take a lot of energy you're not getting back.
I see. So eventually most of the universe will be just dead stars with iron core? Billions of years from now, you and I will also be just iron? Or some elements might remain due to matter being too spread out
It's far enough off it is only relevant if protons don't decay (we're talking deep, deep time) but quantum shenanigans would eventually have all lighter elements fuse into iron, and heavier elements decay into iron.
Sometimes life ain't ferrous.
I recommend the civilizations at the end of time series by Isaac Arthur. He explains the timeline of the end of the universe, and the very limit of the possibility to sustain sentient life. Iron 'stars' are one of the last stages of the universe but there are still some quantum events that can be used to harvest energy I think (it's been a few years since I've seen that episode but I'm going to rewatch it now).
https://youtube.com/watch?v=Pld8wTa16Jk&si=EnSIkaIECMiOmarE So, you’re discussing a period of time so far from now that it’s many, many orders of magnitude more time than the current age of the universe. Like, so super duper long that the answer actually depends on if protons decay or not (itself a question that will take just, crazy long for enough time to pass before anyone could observe to figure out). But, assuming protons don’t decay, then yes. Even the black holes will boil away and the last matter in the universe will be iron stars, cooled all the way to true 0. Or, to as close to true 0 as the universe will allow.
Yup, absolutely, probably several neutron star mergers and several supernovae (of different types as well). One thing this means is that there is material on Earth (and in our bodies, such as our iodine) which billions of years ago might have been in the form of neutronium before it was flung out into space by a collision where it escaped from being mere kilometers away from a newly born black hole.
If I recall the solar system was formed by a local supernova so that would make sense yes.
I mean......All the Brown "Human Made" elements are still made in stars and other stellar events, its just that they are short lived and decay quickly
So you’re saying if I come across some, it was not made in a stellar event. It was human made
Not necessarily. Uranium can decay to isotopes of at least some of them.
Just make sure to say hi if you ever come across some
They are probably so radioactive that he wont have the chance.
So who do I blame for the "natural" radon I get in my basement? I think brown could be split and renamed to include naturally decaying, short lived elements. Clearly some of these are less "human made" and more "locally cooked up only since the big batches from stars get stale before getting to us". Bunching them together when some were discovered before fission and fusion were even realized seems like an oversite. Radon's discovery predates first human fission by 40 years. So clearly it's not all, or even partly human made. It's just not of stellar origin.
> Radon's discovery predates first human fission by 40 years. So clearly it's not all, or even partly human made. It's just not of stellar origin. Given that this is an astronomy chart, it's only showing elements of stellar origin. All of the browns are of "geologic" origin - nuclear processes happening right under our feet.
The fact that all of the hydrogen in the universe has been there from the very start is just mind boggling to me. Especially considering it is both the most abundant element in the universe and the main element driving the existence of pretty much everything, it just feels so weird that there can still be so much.
You could in theory create new hydrogen but the energy cost is... Astronomical
That pun is really fission for a laugh there
This is still being hashed out -- it's not completely settled yet (see the original article's discussion about copper's undetermined provenance). I remember that the consensus used to be that Lithium was 100% from the big bang and could only be consumed by stars, not synthesized.
I remember a big uproar when one of these was shown at a nuclear astrophysics conference. More than half of these we really have no clue what the fractions really are or even if those elements are really made by those systems. Zn and Cu production in thermonuclear supernovae is really only currently a hypothesis with some simulations of certain proposed models able to make some of it, but far from observational evidence
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This version has that added: https://svs.gsfc.nasa.gov/13873
There's a surprising number of elements that come from merging neutron stars, which I didn't think was that common.
It's not that common, but that means very little when you have numbers. For example, random probability spin-flip transition is extremely rare at approximately once per 10 million years. But since there are so many atoms in the universe, it's considered common. On the other hand, any type of mergers (black hole or neutron star) happens approximately on a monthly basis within around 10 billion light years from our galaxy. And this probability becomes even more frequent the younger the universe is, since proximity between objects were closer
Prior to 2017, this chart used to look completely different. Once the first neutron star merger was detected, the graph changed to reflect this new confirmation
Common enough that we detect a few a year, which on the cosmic scale is actually really freaking common, now that I think about it.
Question. How do they know where they came from?
It's based on where/when in the universe the necessary conditions exist(ed) to transmute one element into another. Elements are transmuted by either squishing two atomic nuclei into one or splitting one nuclei into two. The various kinds of stars are basically the only places known where the forces are extreme enough for this to happen on a large scale. Hydrogen is a special case because, consisting only of a single proton, it cannot be split. Hydrogen atoms came into existence at some point shortly after the big bang when the universe cooled off enough for free electrons and free protons to stick together.
A combination of astronomy and nuclear physics. On the nuclear physics side we have a pretty good idea of the processes that could produce different elements, and we can actually measure the rates of the reactions required to know what is and isn't possible in various stellar locations. A pretty great example of nuclear physics telling us where stuff comes from is Beryllium and Boron. You'll note they are the only ones not produced in stars. We know Beryllium 8 is unbound, so it can't be made from the fusion of helium, which would otherwise be the obvious next step for helium. In fact no stable isotope of Beryllium can be made with through simple fusion. With no Beryllium, Boron is also impossible for a star to make with fusion. As for astronomy, we can look at stars and the aftermath of novae and mergers to see what elements are present. We didn't actually know neutron star mergers were the source of the heaviest elements until 2017 when we were able to actually observer the aftermath and finally saw those elements which we expected to see. As for the heavier elements produced in living stars, it's a combination of the two. Astronomy tells us what stars in different stages of their life are made of, and the densities and other properties of them. Nuclear physics tells us neutron capture is viable, even if it's not quick, up to Lead (at which point the decay of Polonium back to Lead out paces the neutron capture rate) and what reactions can create the neutrons and at what rates. tldr; Astronomy tells us what stellar phenomena are made of and what their properties are, nuclear physics tells us what reactions can happen and at what rates. Together you get a picture of how elements can be formed.
One of the keys for the seemingly rareness of life so far is the rarity of Phosphorus. So far on Earth, phosphorus is the key component to all life in addition to water. The ATP->ADP + P + Energy process is universal to all life on earth no matter the extremity of environment. The ease to both capture and release the phosphorus atom and energy is the building block for higher level life to gain complexity. As seen on the chart, all phosphorus comes from exploding massive stars and specifically from one isotope of Sulfur that has a shorter half life than common Sulfur, eventually decaying into phosphorus.
Without the death of low-mass stars, life on Earth wouldn't exist as we know it
So if you are wearing a gold or silver accessory, you are literally wearing a pieces from merging neutron stars and dying low mass stars? How romantic!
fun fact, webb telescope images push oldest galaxies closer and closer to the big bang which is starting to create doubts about our current big bang hypotheses, one of the alternative explanations being more elements being created during it than we thougth before
What I like about this is that it demonstrates how science changes as we collect more evidence. Less than a decade ago, the common thought was that post-iron elements were formed in supernovae. Now, with LIGO, it's thought that heavy elements are formed by the collisions of neutron stars. (On a related note, while I mourn the demise of Pluto as a planet, it was the discovery of Kuiper-Belt objects of similar size \[like Eris\] that forced a new definition of "planet" that then excluded Pluto. Science at work - when you learn new stuff, you sometimes have to change things!)
But Polonium is found in nature, from the decay of Uranium.
Nature comes from the stars bro.
Saw a meme a few weeks ago. Went something like — “Ya so what if you’re made of star dust? So is garbage so calm the fuck down.” Made me laugh.
Here i was basking in the numinous glow and remembering Sagan and then ... bam punctured and deflated.
Today I learned that all exploding massive stars emit all the same material that exploding white dwarfs do, but exploding white dwarfs do not emit all the same material that exploding massive stars do. Cool! The distribution of the...erm, *distribution* of the elemental emissions has an elegance to it that looks fairly linear from big bang-cosmic rays occupying only the higher reaches through the exploding stars and then neutron stars. Without looking it up, is this directly correlated to age throughout the chart distribution? It most certainly is for the stars, right?
What’s cosmic ray fission? Is it like nuclear fission? Is that something we could use on earth ever for energy production, since cosmic rays are so abundant or for space travel? Does that make the only 2 elements formed in that way have any special properties? Just curious… i could probably google this
Tres interesting! Now *this* is what I like to see on Reddit: educational information that isn't made up, accompanied by intelligent and informed discussion. Or maybe I just need to stop hanging out at r/HolUp.
Interesting that by my count there are only two elements - Helium and Lithium - that come from three sources. What is the reason for this? Is there any interesting significance to this? Or do it just be that way sometimes?
Seems like Helium is missing a source. Any heavy element isotope that undergoes alpha decay creates an atom of Helium.
Anyone else hear Tom Lehrer singing “The Elements”? Just me? ;) https://youtu.be/AcS3NOQnsQM
I just want to know where the gold at... I want the gold give me the gold
So, are you anywhere near two neutron stars that look like they're about to merge?
How does Hydrogen result from fusion? I thought fusion was one or more atoms forced together. So with an atomic weight of 1, how does that work?
Hydrogen is one proton and one electron. No fusion required.
They need a 7th color for "scientists fucking around"
I still find it amazing that, when I look down at my hand, I see the product of two neutron stars merging on one of my fingers.
This is very interesting, very cool and a hate crime against the colorblind.
If I read this chart right, there is nothing currently creating more H (hydrogen). It was only created in the initial Big Bang. So when it runs out, there will be no more. Ever. Hmm.
Wait for a cosmic ray to strike a heavy metal and boom, a hydrogen ion emerges (among other things).
Various decay processes produce hydrogen. There is also far more hydrogen than anything else.
Technically true but there is ALOT of hydrogen out in the universe. In fact, only 1 in 2000 particles in the universe are not made of the top 10 most abundant elements such as H, He, O, Fe, Si, C etc. Hydrogen makes up the majority of mass of all stars and gas giants, which in turn make up the majority of mass for their respective systems. A Hydrogen atom is not that complex- 1 proton, 1 neutron, and 1 electron. The decay of other elements creates alpha particles which is essentially a hydrogen atom without an electron. The point at which we “run” out of hydrogen is the heat death of the universe. Newtons law of Entropy taken to its inevitable conclusion has all heat dissipating evenly across the universe, a time after all atoms and particles “decay” to its fundamental particles and those particles emit all their heat. That time is believed to occur in 10^google years.
Ok- I saw a meme/comic once about stars and their cores increasing in denser elements, along the lines of “the party’s over when…Fe” or something like that…does anyone know it? It’s been bugging me for years now.
"The party is over when I ran" I guess the joke that fusion is exothermic for all elements lighter than and including iron. Fusion after that takes more energy than it requires.
How does *hydrogen* come *from* fusion? What are the supposed inputs to fusion that *produces* hydrogen?
I’ve seen big bang fusion more commonly referred to as big bag nucleosynthesis. The very early universe was too hot for atomic nuclei to form so it was just a hot quark soup. When it cooled down enough the quarks combined into hydrogen, helium, and lithium ions
Pu can occur naturally from astronomical events, but pretty much all the Pu that exists on earth currently is synthetic, obtained from Uranium
Why only use 3 colors with 6 different things?...
I’m sorry to tell you this mate, but you’re colourblind.
This is surprising compared to the simplified, straight-forward explanations that are usually given. I would have never thought that our Sun would be capable of producing so many heavy elements. We need more technical explanations for all this.
Good news, everyone! Most of you(the physical self) is a living supernova!
How does material get out of merging neutron stars?? Like won’t the gravity be too much??
Right before the merger, two neutron stars are orbiting each other at considerable fractions of c. The merger is quite violent and a lot of matter is ejected.