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The Phlogiston Model

All of these models are connected through the Ruedenberg principle, which states that the main part of the energy of the covalent bond between atoms is the lower kinetic energy of the valence electrons as they get more space. This is clear from the energy expression of a particle localized in a one-dimensional box that has a length L (derived in Section 2.2)  [Pg.76]

In the bond between electropositive atoms (metals) some of the valence electrons leave the atoms and are distributed over the interstitial holes such that the total energy is minimal. Valence electrons that remain behind on the atoms because [Pg.76]

The Pauli principle accounts for crystal and molecular structures and for the fact that covalent bonding is directed in space. Its quantum-mechanical basis is explained with a simple orbital approach the wavefunction (l, 2) for two electrons that have the same spin (and together form a triplet state) is described by the Slater determinant ab in which a and b indicate the atomic orbitals on atoms a and b. This notation is shorthand for [Pg.78]

Bound electrons merit another name to distinguish them from free electrons because their particle properties (mass, charge, spin) are so different. They are subject to interaction with the surrounding nuclei, which can make them heavier or lighter than unbound free electrons in vacuum. Superconductivity, e.g., is one kind of interaction of electrons with the lattice. [Pg.80]

The name phlogiston was chosen for a bound electron because the alternative proposed, gluon,is already in use by elementary particle physicists for a different particle and also because the word phlogiston already has the form (with the suffix -on) that is usual for the names of elementary particles in physics. Elementary particles such as electrons, photons, tachyons, mesons, fermions, neutrons, leptons, and so on are examples of that syntax. Phlogistons then are localized renormalized chemical electrons. They behave quite like a liquid, and that electron liquid could be called phlogiston. [Pg.80]


In the phlogiston model (Section 2.10) the surrounding charges are the result of the charge transfer and the final Coulomb term is shown to compensate for the chemical hardness. [Pg.68]

Stahl s original idea is now seen to have been partly correct, but as it was not quantitative, it was useless compared to Lavoisier s ideas on oxidation. The phlogiston model fell rightly into oblivion, but recent thinking regarding electronegativity has perhaps partly reinstated it. [Pg.80]

The formalism of the phlogiston model, if it existed, would follow closely that of the Pearson model, with differences being in the extension with interstitials, the Madelung potential, and a second electronegativity parameter to include the homopolar bond. [Pg.81]

If the electronegativity of the atoms is low enough, interstitial holes behave as virtual atoms that have their own electronegativity and hardness and can accept valence electrons. In the phlogiston model, as in the Johnson model, metals are substances that have a cation lattice and interstitial valence electrons. [Pg.83]

The Inorganic 12. What is the relation between chemical hardness and the trans effect (if there is one) Does Chemistry of that fit with the phlogiston model ... [Pg.110]

A ligand field stabilization energy treatment accounts for the inertness of trivalent chromium complexes for ligand exchange. Is the phlogiston model applicable here If so, how ... [Pg.110]

Describe the bonding between the metal atom and the organic ligand in all the organometal compounds discussed in this chapter according to the phlogiston model. [Pg.110]

Z. Jumps in knowledge arise from new theoretical concepts, such as the disproving of the phlogiston hypothesis ("the" paradigm shift) or the atom model of Dalton and the Periodic Table. An equally accelerating effect results from the discovery of new methods, such as electrochemistry, spectral analysis, and X-rays. [Pg.102]

The phlogiston parameters and rj of all the elements could be derived from the ionization energy and the electron affinity as in the Pearson model, but they also can be determined by fitting the theoretical function of the bond energy with experimentally observed values as in the Miedema model. Given the bond length Rq the parameter x and rj for every element can be derived with a least-squares fit. The existence of any compound, its bond energy, and polarity can be simply estimated with these parameters. [Pg.82]

All the examples given by the authors of the different models discussed above are covered by the phlogiston generalization of their models. [Pg.83]

Knowledge of oxygen was a condition for the new model. It is remarkable that it was the two phlogiston spokesmen, Scheele and Priestley, who independently dehv-ered the ammunition that was needed to shoot to pieces the way of thinking based on phlogiston. [Pg.222]

Let us examine briefly the logic of Lavoisier s model of the gaseous state. His earlier view, when he planned to collect and study the fumes emitted from heated metals, appears to have been that the fumes were no more than a simple physical vaporization, the combination of the solid body with the free fire of the direct heat. In his new view, however, the fire that liberates the air from the calx comes from the chemically fixed fire, phlogiston, in the charcoal. [Pg.168]

Guyton s identification of phlogiston with fire, heat, and electric fluid put him in the company of Boerhaave and other physicalists rather than that of other chemists. Phlogiston or fire became an essential part of his dissolution model of chemical action as a kind of universal solvent. Phlogiston was to metals what water was to salts. Just as salts retained the water of crystallization from their dissolution in water, metals retained the fire of crystallisation from their dissolution in fire. Since fire was the greatest solvent, it should be fixed in all bodies in their transition from the fluid to the solid state. Water itself received its fluidity and dissolving power from the fire it contained. Combustible and noncombustible bodies would differ then only in the proportion of the fire... [Pg.254]


See other pages where The Phlogiston Model is mentioned: [Pg.964]    [Pg.76]    [Pg.76]    [Pg.78]    [Pg.80]    [Pg.83]    [Pg.83]    [Pg.193]    [Pg.964]    [Pg.76]    [Pg.76]    [Pg.78]    [Pg.80]    [Pg.83]    [Pg.83]    [Pg.193]    [Pg.124]    [Pg.108]    [Pg.74]    [Pg.255]    [Pg.331]    [Pg.333]    [Pg.393]    [Pg.90]    [Pg.99]    [Pg.104]    [Pg.106]    [Pg.111]    [Pg.121]    [Pg.197]    [Pg.239]    [Pg.246]    [Pg.82]    [Pg.58]    [Pg.221]    [Pg.167]    [Pg.69]    [Pg.15]    [Pg.126]    [Pg.249]    [Pg.253]    [Pg.332]    [Pg.342]    [Pg.394]    [Pg.480]   


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