The Noble Gas Configuration - Not the Driving Force but the Rule of the Game in Chemistry

2009

Angew Chem Int Ed

A closer look: A deeper theoretical understanding of the multifaceted periodic system of elements (PSE) has been achieved in recent years. The large energy gaps above the noble gas shells 1s(2) and np(6) (n=2-6) impress periodicity onto the whole PSE, which is complete with Period 7. The electron configurations of unbound atoms are chemically misleading. The common n+l rule is an example of the "invention of facts" even in the hard sciences.

Section: Discussionmentioning

confidence: 98%

Icon of Chemistry: The Periodic System of Chemical Elements in the New Century

Wang

2009

Angew Chem Int Ed

“…Für Kinetik, Thermodynamik, Stöchiometrie und Rotations- Gefüllte Schalen sind chemisch inaktiv, aber nur wenn sie durch eine große Energielücke von höheren Schalen getrennt sind. [64] Gemäß Reihung (1V) trifft dies für 1s 2 [11,34] Die typischen atomaren Z-IP-Graphen zeigen ausgeprägte Irregularitäten genau bei den Elementen, denen übli-cherweise eine irreguläre Referenzkonfiguration zugeordnet wird. In der Reihe Ca-Zn mit d gÀ2 s 2 -Referenzkonfiguration treten Spitzen bei Cr und Cu auf, wo d gÀ1 s 1 als Referenz gewählt wurde.…”

Section: Resümeeunclassified

Symbol der Chemie: Das Periodensystem der chemischen Elemente im jungen Jahrhundert

Wang

2009

Angewandte Chemie

Auf dem Prüfstand: Das Periodensystem der Elemente (PSE) wird seit kurzem theoretisch besser verstanden. Die großen Energielücken oberhalb der Edelgasschalen 1s2 und np6 (n=2–6) drängen dem ganzen PSE eine Periodizität auf, und mit Reihe 7 ist das PSE komplett. Es zeigt sich, dass die Elektronenkonfigurationen freier Atome chemisch irreführend sind und die (n+l)‐Regel ein Beispiel für die „Erfindung von Tatsachen“ auch in den harten Naturwissenschaften ist.

“…The noble gas shell of O 2) is not stable, except if stabilized by surrounding counterions (O 2) cannot appear in vacuum). As Schmid (2003) coined it: The noble gas configuration is not the driving force but the rule of the game.…”

Section: Quantum Chemical and Philosophical Modelsmentioning

confidence: 99%

Recommended Questions on the Road towards a Scientific Explanation of the Periodic System of Chemical Elements with the Help of the Concepts of Quantum Physics

2006

Found Chem

Periodic tables (PTs) are the 'ultimate paper tools' of general and inorganic chemistry. There are three fields of open questions concerning the relation between PTs and physics: (i) the relation between the chemical facts and the concept of a periodic system (PS) of chemical elements (CEs) as represented by PTs; (ii) the internal structure of the PS; (iii) The relation between the PS and atomistic quantum chemistry. The main open questions refer to (i). The fuzziness of the concepts of chemical properties and of chemical similarities of the CE and their compounds guarantees the autonomy of chemistry. We distinguish between CEs, Elemental Stuffs and Elemental Atoms. We comment on the basic properties of the basic elements. Concerning (ii), two sharp physical numbers (nuclear charge and number of valence electrons) and two coarse fuzzy ranges (ranges of energies and of spatial extensions of the atomic orbitals, AOs) characterize the atoms of the CEs and determine the two-dimensional structure of the PS. Concerning (iii), some relevant 'facts' about and from quantum chemistry are reviewed and compared with common 'textbook facts'. What counts in chemistry is the whole set of nondiffuse orbitals in low-energy average configurations of chemically bonded atoms. Decisive for the periodicity are the energy gaps between the core and valence shells. Diffuse Rydberg orbitals and minute spin-orbit splittings are important in spectroscopy and for philosophers, but less so in chemical science and for the PS.