In reply to Axil Axil's message of Sun, 25 Jan 2015 17:19:46 -0500: Hi, [snip] >This is because neutrons want to be paired with protons to form a >symmetrical nucleus with perfectly shaped lattice based shells.
Pairing is not between protons and neutrons. The pairing energy comes from the magnetic pairing of 2 neutrons with one another and from the pairing of two protons with one another. In both cases, a pair is spin up with spin down. If the pairing was of protons with neutrons, it would make any difference whether they were even or odd, as long as there were equal numbers of protons and neutrons, and the total number of nucleons was even. (e.g. 13 protons with 13 neutrons would also be especially stable, but it aint.) [snip] > >Some nuclides are double-magic, in that the number of protons and neutrons >are both magic, such as helium-4, oxygen-16, calcium-40, calcium-48, >nickel-48, Ni48 is not stable. Even the double magic Ni56 (28,28) is not stable, decaying with a half life of 5.9 days. This is because these isotopes are just too far removed from the center of the curve, for even double magic to be able to make them stable. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
