Abundance of the chemical elements

During the early phases of the Big Bang, nucleosynthesis of hydrogen nuclei resulted in the production of hydrogen and helium isotopes, as well as very minuscule amounts (on the order of 10−10) of lithium and beryllium. There evidence that some boron was produced in the Big Bang, since it has been observed in some very young stars, even though carbon has not.[13] There is agreement that no heavier elements than boron were produced in the Big Bang. As a result, the primordial abundance of atoms consisted of roughly 75% 1H, 25% 4He, and 0.01% deuterium.[14] Subsequent enrichment of galactic halos occurred due to stellar nucleosynthesis and supernova nucleosynthesis.[15] However intergalactic space can still closely resemble the primordial abundance, unless it has been enriched by some means.

The following graph (note log scale) shows abundance of elements in our solar system. The table shows the twelve most common elements in our galaxy (estimated spectroscopically), as measured in parts per million, by mass.[16] Nearby galaxies that have evolved along similar lines have a corresponding enrichment of elements heavier than hydrogen and helium. The more distant galaxies are being viewed as they appeared in the past, so their abundances of elements appear closer to the primordial mixture. As physical laws and processes appear common throughout the visible universe, however, it is expected that these galaxies will likewise have evolved similar abundances of elements.

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