designed:  page 5  iPad  iPhone  Auto Tuned for Win8 Tuned for iPhone 5 Atom Chart Titom Theory MUSE edit fatacy's comment: Titom theory was not forced to cross the Rubicon river finally.
Photodisintegration is endothermic (energy absorbing) for atomic nuclei lighter than iron and sometimes exothermic (energy releasing) for atomic nuclei heavier than iron. - from Wikipedia
Thus, the reason is not something generated by nuclear fusion in the interior of the star, to the future, Gold, Lead, and Plutonium are also drawn in quantum spin style. fatacy's comment: Calcium 40 and Germanium 64 is reserved.
The structure is being complicated and proton neutron in the nucleus is integrated inevitably.
I believe that Calcium 40 continues to radiate a β-ray beyond the space age in particular, and might be a slight gap that occurs in the combination of octahedral and tetrahedral both of strong personality.