Difference between revisions of "?Algebraic Chemistry? Based on a ?PIRT?"

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The present paper continues on from my 2004 PIRT paper entitled ?Can Chemical Data Support a ?PIRT???. The present paper first provides more detail on the variation of ionization potentials within the periods of the Period-ic Table. The description developed refers to the standard quantum numbers n,l,s ( n=1 to infinity, l=0 to n−1, s=−1/2,+1/2) for single-electron states that are incorporated into successively larger atoms. The empiri-cal Madelung and Hund rules that are found in today?s chemistry textbooks provide the nominal filling order for sin-gle-electron states. Using this filling order, a simple empirical formula is developed for the local slopes on a log plot of the ionization potentials. The formula is quite accurate for first ionization potentials, but becomes less accurate for higher-order ionization potentials. This fact could well be related to the fact that the filling order that actually occurs in Nature departs from the standard one for about 20% of the known elements. Accordingly, the filling order for single-electron states is itself investigated next. A more efficacious empirical rule is developed. Like the stan-dard one, it involves sums of traditional quantum numbers, but unlike the standard one, judiciously chosen coeffi-cients that are powers of 2 provide the needed improvements. The resulting formulation automatically directs atten-tion to the elements for which the departures from the textbook rules actually do occur. The paper concludes with an indication of future work.
 
The present paper continues on from my 2004 PIRT paper entitled ?Can Chemical Data Support a ?PIRT???. The present paper first provides more detail on the variation of ionization potentials within the periods of the Period-ic Table. The description developed refers to the standard quantum numbers n,l,s ( n=1 to infinity, l=0 to n−1, s=−1/2,+1/2) for single-electron states that are incorporated into successively larger atoms. The empiri-cal Madelung and Hund rules that are found in today?s chemistry textbooks provide the nominal filling order for sin-gle-electron states. Using this filling order, a simple empirical formula is developed for the local slopes on a log plot of the ionization potentials. The formula is quite accurate for first ionization potentials, but becomes less accurate for higher-order ionization potentials. This fact could well be related to the fact that the filling order that actually occurs in Nature departs from the standard one for about 20% of the known elements. Accordingly, the filling order for single-electron states is itself investigated next. A more efficacious empirical rule is developed. Like the stan-dard one, it involves sums of traditional quantum numbers, but unlike the standard one, judiciously chosen coeffi-cients that are powers of 2 provide the needed improvements. The resulting formulation automatically directs atten-tion to the elements for which the departures from the textbook rules actually do occur. The paper concludes with an indication of future work.
  
[[Category:Scientific Paper]]
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[[Category:Scientific Paper|algebraic chemistry based pirt]]

Latest revision as of 09:56, 1 January 2017

Scientific Paper
Title ?Algebraic Chemistry? Based on a ?PIRT?
Author(s) Cynthia Kolb Whitney
Keywords Algebraic Chemistry
Published 2006
Journal None

Abstract

The present paper continues on from my 2004 PIRT paper entitled ?Can Chemical Data Support a ?PIRT???. The present paper first provides more detail on the variation of ionization potentials within the periods of the Period-ic Table. The description developed refers to the standard quantum numbers n,l,s ( n=1 to infinity, l=0 to n−1, s=−1/2,+1/2) for single-electron states that are incorporated into successively larger atoms. The empiri-cal Madelung and Hund rules that are found in today?s chemistry textbooks provide the nominal filling order for sin-gle-electron states. Using this filling order, a simple empirical formula is developed for the local slopes on a log plot of the ionization potentials. The formula is quite accurate for first ionization potentials, but becomes less accurate for higher-order ionization potentials. This fact could well be related to the fact that the filling order that actually occurs in Nature departs from the standard one for about 20% of the known elements. Accordingly, the filling order for single-electron states is itself investigated next. A more efficacious empirical rule is developed. Like the stan-dard one, it involves sums of traditional quantum numbers, but unlike the standard one, judiciously chosen coeffi-cients that are powers of 2 provide the needed improvements. The resulting formulation automatically directs atten-tion to the elements for which the departures from the textbook rules actually do occur. The paper concludes with an indication of future work.