The process of forming the hydrogen and helium and other trace constituents is often called big bang nucleosynthesis schramm's figures for relative abundances indicate that helium is about 25% by mass and hydrogen about 73% with all other elements constituting less than 2% carroll & ostlie give 23 to 24% helium. Nucleosynthesis activities a star's energy comes from the combining of light elements into heavier elements in a process known as fusion, or nuclear burning it is generally believed that most of the elements in the universe heavier than helium are created, or synthesized, in stars when lighter nuclei fuse to make heavier nuclei. The big bang nucleosynthesis theory predicts that roughly 25% the mass of the universe consists of helium it also predicts about 001% deuterium, and even smaller quantities of lithium the important point is that the prediction depends critically on the density of baryons (ie neutrons and protons) at the time of nucleosynthesis.
With the formation of stars, heavier nuclei were created from hydrogen and helium by stellar nucleosynthesis , a process that continues today. Stellar nucleosynthesis creates heavier elements from hydrogen and helium learn how stars use fusion to produce heavier and heavier nuclei.
Big bang nucleosynthesis predicts a primordial abundance of about 25% helium-4 by mass, irrespective of the initial conditions of the universe.
The big bang model predicts that nucleosynthesis, the process by which the elements formed, began approximately 100 seconds after the big bang driven by the immense.
Big bang nucleosynthesis gamow however, the lack of stable nuclei with atomic weights of 5 or 8 limited the big bang to producing hydrogen and helium. 33 rows big bang nucleosynthesis by the first millisecond yet, hydrogen and.