The Physics
Opus in profectus


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  1. Write something.
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  4. Write something completely different.


  1. God is in the gaps, as they say. The discussion highlighted the magic numbers for protons and neutrons (2, 8, 20, 28, 50, 82, 126), but it also mentioned a few gaps in the nuclides. Namely, there are no stable isotopes with mass number 5 or 8 (numbers that are important later when we study stellar nucleosynthesis) or atomic number 43 or 61 (technetium and promethium). Look closely at the graph of the nuclides and see if you can find any other interesting gaps. (Consider only elements with atomic numbers below lead Z = 82.)
    1. Are there any other atomic mass numbers with no stable isotopes (like 5 or 8)?
    2. What neutron numbers have no stable isotopes?
    3. What do all of these numbers share in common (or maybe, what do they almost all share in common)?
    4. Are there any apparently "non-magic numbers"