3 ms·

Hard to create and the results seem to get more and more unstable, making it very hard to do any science on them. However there is a theorized "island of stabil

by mglz 2y ago

Hard to create and the results seem to get more and more unstable, making it very hard to do any science on them. However there is a theorized "island of stability", where superheavy elements might stick around for a bit longer: https://en.wikipedia.org/wiki/Island_of_stability https://en.wikipedia.org/wiki/Island_of_stability

delecti 2y ago
That theorized island is centered around elements we've already discovered though, being in the range of ~110 protons. So element 120, being discussed, is already well past that point.
- seanw444 2y ago
  Why couldn't there be multiple islands of stability, and why couldn't they be way higher in proton count? All you should really need is a fairly "balanced" nucleus, right? Is there some property of larger nuclei that makes them increasingly more difficult to balance?
  - mannykannot 2y ago
    I just posted some notes on this in another reply: https://news.ycombinator.com/item?id=41057818 https://news.ycombinator.com/item?id=41057818
  - adrian_b 2y ago
    There are with certainty multiple islands of stability, when each layer of nucleons becomes complete. However, in each island of stability the most stable element is much less stable than the most stable element of the previous island of stability. Therefore in most higher islands of stability the decay times will become too short. It is possible and rather likely that only the first undiscovered island of stability may contain relatively long-lived elements, e.g. with half-lives over one second. An island of stability finishes at bismuth, which is radioactive, but which has a huge half-life. The next island of stability contains the long-lived thorium and uranium and the still relatively long-lived neptunium and plutonium, after which the half-lives decrease very quickly. Whichever will be the longest-lived elements of the next island of stability, their half-lives will be many orders of magnitude smaller than those of thorium and uranium.
    - daedrdev 2y ago
      Notably Lead-208 has magic numbers of protons and neutrons so is extra stable, with lead itself representing the last stable element
- adrian_b 2y ago
  The next magic numbers after 82 are not known with certainty. Nevertheless, it was usually supposed that 126 is the next magic number for protons, in which case it has not been reached yet. Other possible values, from more recent computations, are 122 and 124, also not reached yet. Moreover, the isotopes that are the most stable for the already synthesized elements are expected to have more neutrons than in the isotopes that have been successfully produced. So it is not impossible that an "island of stability" might have already been reached, but only with isotopes that have so few neutrons that they remain outside the zone of stability.

by mglz 2y ago

delecti 2y ago

That theorized island is centered around elements we've already discovered though, being in the range of ~110 protons. So element 120, being discussed, is already well past that point.

seanw444 2y ago
Why couldn't there be multiple islands of stability, and why couldn't they be way higher in proton count? All you should really need is a fairly "balanced" nucleus, right? Is there some property of larger nuclei that makes them increasingly more difficult to balance?
- mannykannot 2y ago
  I just posted some notes on this in another reply: https://news.ycombinator.com/item?id=41057818 https://news.ycombinator.com/item?id=41057818
- adrian_b 2y ago
  There are with certainty multiple islands of stability, when each layer of nucleons becomes complete. However, in each island of stability the most stable element is much less stable than the most stable element of the previous island of stability. Therefore in most higher islands of stability the decay times will become too short. It is possible and rather likely that only the first undiscovered island of stability may contain relatively long-lived elements, e.g. with half-lives over one second. An island of stability finishes at bismuth, which is radioactive, but which has a huge half-life. The next island of stability contains the long-lived thorium and uranium and the still relatively long-lived neptunium and plutonium, after which the half-lives decrease very quickly. Whichever will be the longest-lived elements of the next island of stability, their half-lives will be many orders of magnitude smaller than those of thorium and uranium.
  - daedrdev 2y ago
    Notably Lead-208 has magic numbers of protons and neutrons so is extra stable, with lead itself representing the last stable element
adrian_b 2y ago
The next magic numbers after 82 are not known with certainty. Nevertheless, it was usually supposed that 126 is the next magic number for protons, in which case it has not been reached yet. Other possible values, from more recent computations, are 122 and 124, also not reached yet. Moreover, the isotopes that are the most stable for the already synthesized elements are expected to have more neutrons than in the isotopes that have been successfully produced. So it is not impossible that an "island of stability" might have already been reached, but only with isotopes that have so few neutrons that they remain outside the zone of stability.