The rule: punct., style, MOS:CAPS
Okumaya devam et...
← Previous revision | Revision as of 00:35, 4 May 2024 |
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| == The rule == | == The rule == |
| The early form of the rule derived from Harkin's 1917 study of meteorites. He reasoned as others at the time, that meteorites are more representative of the cosmological abundance of the elements. Harkins observed that even atomic number (Z) elements were about 70 times more abundant than those with odd Z. The first seven elements, making up almost 99% of the material in a meteorite, were all even numbered Z. In addition, he observed that 90% of the material consisted of only 15 different isotopes, with atomic weights in multiples of four, the approximate weight of [[alpha particles]]. Three years earlier, Oddo made a similar observation for elements in the Earth's crust, speculating that elements are condensation products of [[helium]]. The nuclear core of Helium is the same as an alpha particle.<ref name=KraghGeochemsitry>{{Cite journal |last=Kragh |first=Helge |date=2000 |title=An Unlikely Connection: Geochemistry and Nuclear Structure |url=http://link.springer.com/10.1007/s000160050051 |journal=Physics in Perspective |volume=2 |issue=4 |pages=381 |doi=10.1007/s000160050051|bibcode=2000PhP.....2..381K }}</ref>{{rp|385}} | The early form of the rule derived from Harkin's 1917 study of meteorites. He reasoned as others at the time, that meteorites are more representative of the cosmological abundance of the elements. Harkins observed that elements with even atomic numbers (''Z'') were about 70 times more abundant than those with odd ''Z''. The first seven elements, making up almost 99% of the material in a meteorite, were all even-numbered ''Z''. In addition, he observed that 90% of the material consisted of only 15 different isotopes, with atomic weights in multiples of four, the approximate weight of [[alpha particles]]. Three years earlier, Oddo made a similar observation for elements in the Earth's crust, speculating that elements are condensation products of [[helium]]. The nuclear core of helium is the same as an alpha particle.<ref name=KraghGeochemsitry>{{Cite journal |last=Kragh |first=Helge |date=2000 |title=An Unlikely Connection: Geochemistry and Nuclear Structure |url=http://link.springer.com/10.1007/s000160050051 |journal=Physics in Perspective |volume=2 |issue=4 |pages=381 |doi=10.1007/s000160050051 |bibcode=2000PhP.....2..381K }}</ref>{{rp|385}} |
| This early work connection geochemistry with nuclear physics and cosmology was greatly expanded by the Norwegian group created by [[Victor Goldschmidt]]<ref name=KraghGeochemsitry/>{{rp|389}} | This early work connection geochemistry with nuclear physics and cosmology was greatly expanded by the Norwegian group created by [[Victor Goldschmidt]].<ref name=KraghGeochemsitry/>{{rp|389}} |
| == Relation to stellar nucleosynthesis == | == Relation to stellar nucleosynthesis == |
| [[File:Light nuclide abundance and origins hi res.png|thumb|450x450px|Nucleosynthetic origins of light nuclides. The most abundant nuclides have equal numbers of protons and neutrons (box around isotopic symbol). Products of cosmic ray spallation are the least abundant.]] | [[File:Light nuclide abundance and origins hi res.png|thumb|450x450px|Nucleosynthetic origins of light nuclides. The most abundant nuclides have equal numbers of protons and neutrons (box around isotopic symbol). Products of cosmic ray spallation are the least abundant.]] |
Okumaya devam et...