Timeline for Why is technetium unstable?
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7 events
| when toggle format | what | by | license | comment | |
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| Feb 5, 2016 at 8:13 | comment | added | Phil | Great, I didn't know that part of the story. So angular momentum gives us the sequence 2, 6, 10, 14, 18, 22..., and when we cumulatively add those numbers together we get 2, 8, 18, 32, 50, 72..., which are the numbers I mentioned in the original post. It all fits together beautifully now | |
| Jan 29, 2016 at 19:07 | comment | added | rob♦ | The sequences actually come from the number of fermions you can fit into an orbital with angular momentum $L$, which is $2(2L+1)$. This is why the periodic table has columns in groups of two (electrons with $L=0$), six ($L=1$), ten ($L=2$), and fourteen ($L=3$). But yes, you've got the gist of it. | |
| Jan 29, 2016 at 9:24 | comment | added | Phil | Thanks Rob! The numbers 2, 10, 18, 36, 54, 86, 118 are computed by cumulatively adding 2, 8, 8, 18, 18, 32, 32, which are all among the numbers I mentioned. The early magic numbers also approximately correspond with these numbers, though as you say, physics is more complicated than pure mathematics. But as a rough rule-of-thumb, it's not too bad :-) | |
| Jan 29, 2016 at 7:13 | comment | added | rob♦ | Welcome to Physics.SE! This answer is essentially correct, but neither the electronic closed shells (2, 10, 18, 36, 54, 86, 118(?)) nor the nuclear magic numbers (2, 8, 20, 28, 50, 82, 126) follow the pattern you have named — the physics is more complicated than $2n^2$. | |
| Jan 29, 2016 at 6:14 | review | Late answers | |||
| Jan 29, 2016 at 6:20 | |||||
| Jan 29, 2016 at 5:50 | review | First posts | |||
| Jan 29, 2016 at 7:03 | |||||
| Jan 29, 2016 at 5:47 | history | answered | Phil | CC BY-SA 3.0 |