Nucleosynthesis of The Elements This page is concerned with where the chemical elements come from: It is a long story, largely deduced in the second half of the twentieth century, that ultimately and rather romantically says:
See Article History Nucleosynthesis, production on a cosmic scale of all the species of chemical elements from perhaps one or two simple types of atomic nuclei, a process that entails large-scale nuclear reactions including those in progress in the Sun and other stars.
Chemical elements differ from one another on the basis of the number of protons fundamental particles that bear a positive charge in the atomic nuclei of each. Species of the same element, or isotopes, in addition, differ from each other in mass or on the basis of the number of neutrons neutral fundamental particles in their nuclei.
Nuclear species can be transformed into other nuclear species by reactions that add or remove protons or neutrons or both. Many of the chemical elements up to iron atomic number 26 and their present cosmic abundances may be accounted for by successive nuclear fusion reactions beginning with hydrogen and perhaps some primeval helium.
By repeated nuclear fusion, four hydrogen nuclei amalgamate into a helium nucleus. Helium nuclei, in turn, can be built up into carbon three helium nucleioxygen four helium nucleiand other heavier elements. Elements heavier than iron and some isotopes of lighter elements may be accounted for by capture of successive neutrons.
The capture of a neutron increases the mass of a nucleus; subsequent radioactive beta decay converts a neutron into a proton with ejection of an electron and an antineutrinoleaving the mass practically unchanged.
The increase in the number of protons builds the nucleus to higher atomic numbers. Learn More in these related Britannica articles:Nucleosynthesis is the process of creating new atomic nuclei from preexisting nucleons (protons and neutrons). The primordial preexisting nucleons were formed from the quark-gluon plasma of the.
Nucleosynthesis of The Elements This page is concerned with where the chemical elements come from: how atomic nuclei are forged. It is a long story, largely deduced in the second half of the twentieth century, that ultimately and rather romantically says: We Are Stardust.
Heavy Element Nucleosynthesis A summary of the nucleosynthesis of light elements is as follows 4He Helium burning 3He Incomplete PP chain (H burning) 2H, Li, Be, B Non-thermal processes (spallation) 14N, 13C, 15N, 17O CNO processing 12C, 16O Helium burning 18O, 22Ne α captures on 14N (He burning).
Stellar nucleosynthesis is the theory explaining the creation (nucleosynthesis) of chemical elements by nuclear fusion reactions between atoms within the stars. Stellar nucleosynthesis has occurred continuously since the original creation of hydrogen, helium and lithium during the Big urbanagricultureinitiative.com is a highly predictive theory that today yields .
Among the elements found naturally on Earth (the so-called primordial elements), those heavier than boron were created by stellar nucleosynthesis and by supernova nucleosynthesis.
They range in atomic numbers from Z=6 (carbon) to Z=94 (plutonium).
Precisely which elements are involved in nucleosynthesis depends on the age and mass of the star. The most prevalent reaction in smaller stars like our Sun is the fusion of hydrogen into helium by the proton-proton chain ; in more massive stars this fusion occurs via the carbon cycle.