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Shells, in atoms

The Pauli exclusion principle states that no two electrons in the same atom can have the same set of four quantum numbers. Along with the order of increasing energy, we can use this principle to deduce the order of filling of electron shells in atoms. [Pg.255]

It should be emphasized that, in each case, the mathematics determine maximum occupancy of respective shells. In atoms, partially filled shells have unfilled orbitals that will readily accept electrons, which become the basis for chemical reactions, such as ionization or bonding. A filled shell is seen as a satisfied valency which requires more extreme conditions to elicit further chemical reactivity. Similarly, unfilled shells in dendrimers possess reactive sites that may be further modified under conditions similar to those used to construct the dendrimer. Filled shells in dendrimers require more vigorous conditions for further modifications. [Pg.214]

In some cases, a further parallel can be drawn between the order of filling of electron orbitals and the order of filling a dendrimer shell. In atomic Aufbau, electrons are placed in each p or d orbital until each orbital contains one electron before any pairing of electrons within the orbitals takes place. In the preparation of poly(amidoamine) dendrimers, there is a significant difference in the rates of the first and second alkylation of a given amine such that most of the primary amines are converted to secondary amines before the conversion to tertiary amines becomes the predominant process. This can be viewed as analogous to the orbital filling and can, within the limits of the selectivity of the alkylation, be used in the control of dendrimer valence . [Pg.214]

The concept of filled and unfilled electron shells in atoms is extremely important for understanding how atoms behave around other atoms. Filled shells are usually quite stable and generally correspond to lower energies than unfilled shells. So in a sense, atoms fiike" to have filled electron shells. Different orbitals can accommodate different numbers of electrons, so what constitutes a filled shell depends on the orbitals involved. Filled v orbitals contain two electrons, filled p orbitals contain six electrons, and filled d orbitals contain ten electrons. See Table 1.1. [Pg.10]

Aufbau ( building up ) Principle A guide for predicting the order in which electrons fill subshells and shells in atoms. [Pg.225]

W. Woznicki, in Theory of Electronic Shell in Atoms and Molecules edited by A. Jucys (Mintis, Vilnius, 1971) p. 103-6. [Pg.226]

Briefly explain why atomic emission spectra provide experimental evidence for the existence of electron energy levels (shells) in atoms. [Pg.45]

Meanwhile N. Bohr was working on the theory of electron shells in atoms which also became the corner-stone of the periodic system theory and, at last, explained the periodic changes in the properties of chemical elements. Bohr also solved the problem which had interested chemists for many years he found the exact number of rare-earth elements. There had to be fifteen of them from lanthanum to lutetium. Only one REE between neodymium and samarium (later known as promethium, see p. 208) remained unknown. Bohr came to this conclusion on the basis of the laws found by him which governed the formation of electron shells of atoms with increasing Z. [Pg.168]

Complete electron shells in atom Quantum number Orbital angular momentum along line joining atom centers Complete electron groups in molecule... [Pg.11]

Each function has a particular symmetry (like electron shells in atoms have flieir own symmetry p, d, etc.). The angular dependencies of the first two polynomials are plotted in Fig. 3.16. [Pg.30]

Although many models have been elaborated for the description of nuclear structure, the shell model is of central importance. In this section, the most important experimental facts indicating the existence of magic numbers (closed shells) in atomic nuclei are summarized. Then the independent-particle shell model of spherical and deformed nuclei, and the shell model with multiparticle configurations will be treated. [Pg.63]

W. R. Johnson, K. T. Cheng. Relativistic and quantum electrodynamic effects on atomic inner shells (in Atomic inner-shell physics). Physics of Atoms and Molecules, p. 3-30, New York, London, 1985. Plenum Press. [Pg.683]

Associated with Unsaturated Outer Shells in Atomic Elements and in Dendrimers... [Pg.358]

Deduce the electronic configurations of the valence shells in atoms of gallium and lead. [Pg.94]

Woznicki W (1971) In Jucys A (ed) Theory of electronic shells in atoms and molecules. Mintis, Vilnius, p 103... [Pg.117]

Solvation can be included in calculations implicitly (e.g., in PB-SCRF, PCM/DIR, SM2, and other continuum solvent models that emulate properties of bulk solvent at varying degrees of sophistication) or explicitly (by placing solvent molecules around the solute). The former approach is arguably more widely used, probably owing to the computational efficiency of implicit solvation and the avoidance of the compUcating issue of explicit solvent placement. Nevertheless, the sacrifice of atomic detail for the solvent is not always justified and recently, a hybrid explicit/implicit solvation method was proposed, treating the first solvation shell in atomic detail and the remainder of the solvent with a SCRF model [29]. [Pg.196]


See other pages where Shells, in atoms is mentioned: [Pg.2392]    [Pg.25]    [Pg.292]    [Pg.640]    [Pg.56]    [Pg.2392]    [Pg.240]    [Pg.13]    [Pg.39]    [Pg.63]    [Pg.202]    [Pg.67]   
See also in sourсe #XX -- [ Pg.2 , Pg.3 , Pg.4 , Pg.5 , Pg.16 ]




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