- Primordial element
geochemistry", Primordial elements are chemical elements found on the earth that have existed in their current form since before the earth was formed, according to accepted stellar evolutiontheory. This means that the half-lifeon the given atoms must be greater than about 108 years.
All stable elements are primordial, as are some
radioactiveelements including thorium(due to isotope 232), and uranium. It has also been shown that plutoniumis primordial, although just barely as its most stable isotope ( plutonium-244) concentration in ores is nearly undetectable.
Some unstable isotopes which occur naturally (such as
carbon-14, tritium, and plutonium-239) are not primordial, as they must be constantly regenerated by stellar radiation (in the case of carbon and tritium) or geochemical transmutation (in the case of plutonium). Heliumis unusual; most of it would have escaped Earth's gravitational pull as it was forming. Most helium is mined and comes as a result of radioactive decay in the core of the earth, so it is difficult to characterize helium as primordial.
astrochemistry", primordial elements are chemical elements which were synthesized in the first round of nuclear synthesis after the big bang. These are believed to include only hydrogen, helium, lithium, and beryllium. To produce heavier atoms, stellar nuclear synthesis is required. For this reason it is known that the sun is not a first-generation star.
Origin of life
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Primordial — Pri*mor di*al, n. A first principle or element. [1913 Webster] … The Collaborative International Dictionary of English
Élément mononucléidique — Ne doit pas être confondu avec élément monoisotopique, élément avec un seul isotope stable. Un élément mononucléidique est un élément qui n est naturellement présent sur Terre que sous la forme d un seul nucléide, que celui ci soit stable… … Wikipédia en Français
Élément monoisotopique — Ne doit pas être confondu avec élément mononucléidique, élément avec un seul isotope significativement abondant. Un élément monoisotopique est un élément ne possédant qu un seul isotope stable. À l heure actuelle, on dénombre 26 éléments… … Wikipédia en Français
Monoisotopic element — Not to be confused with the 22 mononuclidic elements, defined as those with only one significant naturally abundant nuclide. A monoisotopic element is one of 26 chemical elements which have only a single stable isotope (nuclide). A list is given… … Wikipedia
Mononuclidic element — Not to be confused with the 26 monoisotopic elements defined as having only one stable nuclide. Set A is the 26 monoisotopic elements and B the 22 mononuclidic elements. The intersection consists of 19 elements that are both, but each set… … Wikipedia
Group 6 element — Group → 6 ↓ Period 4 24 Cr 5 … Wikipedia
Group 11 element — Group → 11 ↓ Period 4 29 Cu 5 … Wikipedia
Group 10 element — Group 10 redirects here. For the rugby league competition, see Group 10 Rugby League. Group → 4 ↓ Period 4 … Wikipedia
Group 9 element — Group → 4 ↓ Period 4 27 Co 5 … Wikipedia
Period 2 element — A period 2 element is one of the chemical elements in the second row (or period) of the periodic table of the chemical elements. The periodic table is laid out in rows to illustrate recurring (periodic) trends in the chemical behaviour of the… … Wikipedia