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8O Oxygen is the first element where the addition of an additional neutron to an EO8O17 isotope with 1 extra neutron results in an EE8O18 isotope that is stable with 2 extra neutrons, rather than in its being converted to a new and stable A=2Z isotope. It is stated that the rest mass plus free energy of the isotope EE8O18 is less than that of the alternative isotope OO9F18 and that therefore an isotope of OO9F18 will spontaneously decay to EE8O18 by positron emission, with a conversion halflife time period of 1.829 hours (=10E+3.818+seconds). It is therefor used internally for positive tomography tests. This evidently involves the internal conversion of a proton into a neutron within the atom as is the case in all the beta+ emission occurrences. In less Zvalue occurrences of this nature the conversion process is that of the added neutron being converted into a proton by a beta- (electron) emission process. The only problem with this in the case of 8O18 is concerned with the possibility that the 8 protons of the atom are already paired with the 8 neutrons to form 8 deuteron pair sub sections of the atom. And the disassociation (unpairing) of a deuteron requires an excitation energy of .002388 amu units(or 2.23 mev). So if the 9th added neutron is unpaired so that it can form stable EE8O18, It also looks like it should also be able to alternatively convert and pair up to form OO9F18 and wind up with a lower 9F18 atomic mass value than that of 8O18. But there is no reported existence of a lower (ground) state of the isotope 9F18 with a lower atomic mass value.WFPM (talk) 02:51, 6 September 2009 (UTC)