Editing Big Bang nucleosynthesis (section)

===Heavy elements===
{{Nucleosynthesis periodic table.svg}}
Big Bang nucleosynthesis produced very few nuclei of elements heavier than [[lithium]] due to a bottleneck: the absence of a stable nucleus with 8 or 5 [[nucleon]]s. This deficit of larger atoms also limited the amounts of lithium-7 produced during BBN. In [[stellar nucleosynthesis|stars]], the bottleneck is passed by triple collisions of helium-4 nuclei, producing [[carbon]] (the [[triple-alpha process]]). However, this process is very slow and requires much higher densities, taking tens of thousands of years to convert a significant amount of helium to carbon in stars, and therefore it made a negligible contribution in the minutes following the Big Bang.

The predicted abundance of CNO isotopes produced in Big Bang nucleosynthesis is expected to be on the order of 10<sup>−15</sup> that of H, making them essentially undetectable and negligible.<ref name=iop>{{Cite journal |doi = 10.1088/1742-6596/665/1/012001|title = Primordial Nucleosynthesis|journal = Journal of Physics: Conference Series|volume = 665|pages = 012001|year = 2017|last1 = Coc|first1 = A|arxiv = 1609.06048| s2cid=250691040 }}</ref> Indeed, none of these primordial isotopes of the elements from beryllium to oxygen have yet been detected, although those of beryllium and boron may be able to be detected in the future. So far, the only stable nuclides known experimentally to have been made during Big Bang nucleosynthesis are protium, deuterium, helium-3, helium-4, and lithium-7.<ref>{{Cite arXiv |eprint = 1403.4156v1|last1 = Coc|first1 = Alain|title = Revised Big Bang Nucleosynthesis with long-lived negatively charged massive particles: Impact of new 6Li limits, primordial 9Be nucleosynthesis, and updated recombination rates|last2 = Vangioni|first2 = Elisabeth|class = astro-ph.CO|year = 2014}}</ref>