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The periodic table, colour coded by the likely origin of each element

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Re: The periodic table, colour coded by the likely origin of each element

#41

Post by [deleted] »

WorldMaker wrote: post #33
arethuza wrote: post #10

For some completely irrational reason I was slightly disappointed that the gold in my wedding ring was only from a neutron star merger and probably not from a supernova. However, reading the relevant wikipedia page I came across this part: "this single neutron star merger event generated between 3 and 13 Earth masses of gold" https://en.wikipedia.org/wiki/Gold#Gold_production_in_the_Un... Can't wait to refer to that…

Neutron Star Mergers & Acquisitions sounds like a great title for book or TV show.

[deleted]

Re: The periodic table, colour coded by the likely origin of each element

#42

Post by jcranmer »

Waterluvian wrote: post #24
hermitcrab wrote: post #21

Earlier quoted context omitted.

The process that drives stars is fusion, which turns light elements into heavier (strictly greater atomic number) elements, up to iron. Elements heavier than iron are created in supernovas, neutron star collisions etc. Many heavier elements are unstable and will radioactively decay into light elements. So it is a continual process both ways.

Do they decay to some stable middle region or are they decaying right back down to hydrogen? I’m guessing this is about entropy to an extent.

The most stable element is iron, in terms of having the optimal binding energy (you gain energy for fusing lighter elements into iron, you gain energy for splitting heavier elements into iron). If proton decay doesn't exist, then the trend of all matter would be to turn into iron. If proton decay does exist, then iron itself would decay to less stable elements because the protons in iron would disappear, and the neutron-rich lighter elements would be subject to radioactive decay.

It is unknown how stable our stable nuclei are. Bismuth-209 was long listed as a stable nuclide, until a decay event was observed in 2003, establishing its half life of about 10¹⁹ years (by contrast, the universe is about 10¹⁰ years old).

Re: The periodic table, colour coded by the likely origin of each element

#43

Post by hermitcrab »

typon wrote: post #29
Waterluvian wrote: post #24

Earlier quoted context omitted.

Do they decay to some stable middle region or are they decaying right back down to hydrogen? I’m guessing this is about entropy to an extent.

Over a long enough time span, even protons will decay.

I don't believe that has been observed. So no-one knows for sure.

Re: The periodic table, colour coded by the likely origin of each element

#44

Post by hermitcrab »

Waterluvian wrote: post #24
hermitcrab wrote: post #21

Earlier quoted context omitted.

The process that drives stars is fusion, which turns light elements into heavier (strictly greater atomic number) elements, up to iron. Elements heavier than iron are created in supernovas, neutron star collisions etc. Many heavier elements are unstable and will radioactively decay into light elements. So it is a continual process both ways.

Do they decay to some stable middle region or are they decaying right back down to hydrogen? I’m guessing this is about entropy to an extent.

Memory is a bit rusty on this (30 years since I did nuclear physics) but elements have stable and unstable isotopes (with the same number of protons and a different number of neutrons). E.g. Carbon 12 and 13 are stable and Carbon 14 is unstable (half-life 5730 years). An atom will keep decaying until it reaches a stable form. Then it will stay like that until some nuclear fusion or fission event occurs.

Re: The periodic table, colour coded by the likely origin of each element

#45

Post by hermitcrab »

hermitcrab wrote: post #44
Waterluvian wrote: post #24

Earlier quoted context omitted.

Do they decay to some stable middle region or are they decaying right back down to hydrogen? I’m guessing this is about entropy to an extent.

Memory is a bit rusty on this (30 years since I did nuclear physics) but elements have stable and unstable isotopes (with the same number of protons and a different number of neutrons). E.g. Carbon 12 and 13 are stable and Carbon 14 is unstable (half-life 5730 years). An atom will keep decaying until it reaches a stable form. Then it will stay like that until some nuclear fusion or fission event occurs.

Consequently most chains of decay will reach a stable form long before they get to Hydrogen.

Re: The periodic table, colour coded by the likely origin of each element

#46

Post by identity0 »

jacknews wrote: post #3

The image shown by wikipedia https://en.wikipedia.org/wiki/Chemical_element seems more complete and better laid out, and is also by cmglee ( https://commons.wikimedia.org/wiki/User:Cmglee ), based on data from Jennifer Johnson at Ohio State University ( http://www.astronomy.ohio-state.edu/~jaj/nucleo/ ): https://upload.wikimedia.org/wikipedia/commons/3/31/Nucleosy...

Brown: made by monkeys on terrestrial planets

Re: The periodic table, colour coded by the likely origin of each element

#47

Post by nwallin »

altcognito wrote: post #13

This table raises a lot of questions for me: How does a "merged" neutron star, "unmerge?" Or is most of the Au of the universe tied up in neutron stars? And how does that work given that neutron stars are mostly... neutrons?

A neutron star "merger" is a collision between two of the hottest, densest objects in the universe that are still objects. These collisions are incredibly messy and energetic. Stuff gets blown everywhere - a lot of stuff.

Once freed and blown out into space, the remaining neutronium is incredibly unstable without the intense gravitational pressures holding it together. It will rapidly decay into relatively stable material.

Re: The periodic table, colour coded by the likely origin of each element

#48

Post by Diederich »

ncmncm wrote: post #38
BurningFrog wrote: post #15

Earlier quoted context omitted.

They didn't land on the planet, they formed it.

Some did, some didn't. All the iridium, platinum, gold we find landed.

> All the iridium, platinum, gold we find landed

Cool. Do you have a quick reference for the 'landed' part? As opposed to being part of the planet from the beginning. Thanks!

Re: The periodic table, colour coded by the likely origin of each element

#49

Post by BurningFrog »

ncmncm wrote: post #38
BurningFrog wrote: post #15

Earlier quoted context omitted.

They didn't land on the planet, they formed it.

Some did, some didn't. All the iridium, platinum, gold we find landed.

I've been wondering about that.

Is it because all heavy elements present when Earth formed sank to the center?

That would make sense, but I've assumed that since we can mine gold, that's not what happened. If all the gold fell from the sky, that would explain things.

Re: The periodic table, colour coded by the likely origin of each element

#50

Post by dredmorbius »

Tepix wrote: post #39
AllegedAlec wrote: post #12

Earlier quoted context omitted.

Our sun is about 4.6B year old. There were a few other generations of stars that lived and died before our sun came about, and these spewed out the heavier elements that make up our solar system.

It must have been a somewhat dull first generation of stars and planets with only Hydrogen and Helium around. On the other hand, giant stars explode after just a few million years so it didn't take long for other elements to appear.

The ratio of heavier elements to H & He is called metallicity, and it is a measurable characteristic of stars, which are classed into Type I (high metallicity) and Type II (low) populations. Low-metallicity Type II stars are generally older.

Nothing specific on what Type II stellar systems and planets would be like, though I'd suspect gas giants, generally.

https://en.wikipedia.org/wiki/Metallicity

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