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My main reasoning is because 126 being a magic neutron number makes isotopes with 128 neutrons extremely unstable (e.g. 212Po), shouldn't 126 also being a proton magic number make element 128 extremely radioactive? 24.115.255.37 (talk) 02:18, 5 May 2024 (UTC)[reply]
We don't know that 126 is a magic proton number in the first place. It's quite possible, based on current models, that proton shell closures only give a weak effect here and that it's the neutron shell closure at 184 that really matters for SHE stability. OTOH, I agree with the general idea: we are probably going to have a hard time once N = 184 is passed. Double sharp (talk) 08:44, 6 May 2024 (UTC)[reply]
The same effect is also observed in the vicinity of 208Pb, where there are some reasonably long-lived polonium isotopes but alpha half-lives fall by many orders of magnitude at neutron number 128. And indeed, the stabilizing effect for a proton shell at 126, if it even is a magic number, is not agreed upon in different models. It'll be a long time anyway before we can synthesize these elements. –a sock of ComplexRational (talk) 15:47, 6 May 2024 (UTC)[reply]
Hi, read an interesting article postulating a mechanism where the actual inner electrons themselves might add stability by radiating enough energy via the Cherenkov mechanism for unstable nuclei to in fact be meta-stable. This would be a mechanism where theoretically impossible (eg element 164) believed to be found in deep space could have very novel chemistry.
As of yet it is pretty strange stuff but gold and copper are a test case here as their colour is due to relativistic effects.
In actual fact because electrons can be paired they can in fact appear to go faster than light but only a very small fraction of them (0.000001%) and this may in fact be evidence of physics beyond the Standard Model. 91.190.161.160 (talk) 17:16, 29 May 2024 (UTC)[reply]
Ah, now that I wouldn't be so sure of. With all the intruder levels dropping down like 9s and 9p1/2 into period 8, the 8th and 9th periods could very well have different lengths. Assuming it makes sense to talk about elements that far up in the first place, which we also don't know. Better to wait for more computations. :) Double sharp (talk) 12:29, 30 August 2024 (UTC)[reply]
I mean, the lanthanides and actinides have the same length, and I predict Unbiunides and Unseptpentides will also have the same length.
But I get what you're saying, we should wait for more computations for a more accurate extended periodic table. HAt12:33, 30 August 2024 (UTC)[reply]
Yeah, what I mean is that we don't know precisely what orbitals will drop down. It's not out of the question that 6h will fill alongside 10s, which would extend row 9. I don't dare to guess. :) Double sharp (talk) 12:42, 30 August 2024 (UTC)[reply]
I predict the pattern of the 8th period will not use Fricke and Pyykkö’s models, but rather follow the Aufbau principle, meaning the 6f subshell starts at Z = 139, not 143.
I think the isotope 356Uth, with a proton-to-neutron ratio of 1:1.618 (following the trend), might be somewhat stable, with a predicted half life of around 6 to 10 seconds.
Yes, the name is not technically correct. It's not uncommon because there's nothing actually above 121, but really the relationship between Ac and 121 is only secondary: they both have 3 valence electrons, but the set of valence orbitals is not quite analogous (similar to the Al-Sc relationship). Double sharp (talk) 07:50, 3 December 2024 (UTC)[reply]