Magic of chemistry pdf

126 is so far only known to be a magic number for neutrons. 126, which are realized in spherical nuclei, theoretical calculations predict that nuclei in the island of stability are deformed. It is now believed that the sequence of spherical magic numbers cannot be extended in this way. Further predicted magic numbers magic of chemistry pdf 114, 122, 124, and 164 for protons as well as 184, 196, 236, and 318 for neutrons.

Maria Mayer, the very strong evidence for the closed shells. It seemed a little like magic to him, and that is how the words ‘Magic Numbers’ were coined. Double-magic effects may allow existence of stable isotopes which otherwise would not have been expected. 20 neutrons and 20 protons, which is the heaviest stable isotope made of the same number of protons and neutrons. 48 are double magic because calcium-48 has 20 protons and 28 neutrons while nickel-48 has 28 protons and 20 neutrons.

Calcium-48 is very neutron-rich for such a light element, but like calcium-40, it is made stable by being double magic. Nickel-48, discovered in 1999, is the most proton-rich isotope known beyond helium-3. Magic effects can keep unstable nuclides from decaying as rapidly as would otherwise be expected. Nuclear shells are said to occur when the separation between energy levels is significantly greater than the local mean separation. Hence, the “atomic magic numbers” are 2, 10, 18, 36, 54, 86 and 118. In 2010, an alternative explanation of magic numbers was given in terms of symmetry considerations.