<P> During the early phases of the Big Bang, nucleosynthesis of hydrogen nuclei resulted in the production of hydrogen - 1 (protium, H) and helium - 4 (He), as well as a smaller amount of deuterium (H) and very minuscule amounts (on the order of 10) of lithium and beryllium . Even smaller amounts of boron may have been produced in the Big Bang, since it has been observed in some very old stars, while carbon has not . It is generally agreed that no heavier elements than boron were produced in the Big Bang . As a result, the primordial abundance of atoms (or ions) consisted of roughly 75% H, 25% He, and 0.01% deuterium, with only tiny traces of lithium, beryllium, and perhaps boron . Subsequent enrichment of galactic halos occurred due to stellar nucleosynthesis and supernova nucleosynthesis . However, the element abundance in intergalactic space can still closely resemble primordial conditions, unless it has been enriched by some means . </P> <P> On Earth (and elsewhere), trace amounts of various elements continue to be produced from other elements as products of nuclear transmutation processes . These include some produced by cosmic rays or other nuclear reactions (see cosmogenic and nucleogenic nuclides), and others produced as decay products of long - lived primordial nuclides . For example, trace (but detectable) amounts of carbon - 14 (C) are continually produced in the atmosphere by cosmic rays impacting nitrogen atoms, and argon - 40 (Ar) is continually produced by the decay of primordially occurring but unstable potassium - 40 (K). Also, three primordially occurring but radioactive actinides, thorium, uranium, and plutonium, decay through a series of recurrently produced but unstable radioactive elements such as radium and radon, which are transiently present in any sample of these metals or their ores or compounds . Three other radioactive elements, technetium, promethium, and neptunium, occur only incidentally in natural materials, produced as individual atoms by nuclear fission of the nuclei of various heavy elements or in other rare nuclear processes . </P> <P> Human technology has produced various additional elements beyond these first 94, with those through atomic number 118 now known . </P> <P> The following graph (note log scale) shows the 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 . 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, scientist expect that these galaxies evolved elements in similar abundance . </P>

Who was the first scientist to suggest that different elements contain different types of atoms