Processes[ edit ] There are a number of astrophysical processes which are believed to be responsible for nucleosynthesis. This characteristic is reflected in the low abundance of these simple species.
In contrast, the radioactive nuclide beryllium-7 falls into this light element range, but this nuclide has a half-life too short for it to have been formed before the formation of the solar system, so that it cannot be a primordial nuclide.
Google Scholar Boesgaard, A. Claytonfollowed by many others. Timeline[ edit ] Periodic table showing the origin of each element. Google Scholar Duncan, D. It is thought that the primordial nucleons themselves were formed from the quark—gluon plasma during the Big Bang as it cooled below two trillion degrees.
A few minutes afterwards, starting with only protons and neutronsnuclei up to lithium and beryllium both with mass number 7 were formed, but hardly any other elements. As it turned out, spallation could not generate much deuterium, however, the new studies of spallation showed that this process could generate lithium, beryllium and boron, and indeed these isotopes are over-represented in cosmic ray nuclei, as compared with solar atmospheres whereas hydrogen and helium are present in about primordial ratios in cosmic rays.
Those abundances, when plotted on a graph as a function of atomic number, have a jagged sawtooth structure that varies by factors up to ten million. Google Scholar Vangioni-Flam, E. Download preview PDF.
Gradually it became clear that hydrogen and helium are much more abundant than any of the other elements.