Separation energy plots

FIGURE 10.6 Separation energy plot giving energy required to remove a nucleon from any nucleus. Reproduced from P.A. Cox, The Elements, Oxford University Press, Oxford, 1989, p. 38 (with permission). 

Some representative plots of entropies of adsorption are shown in Fig. XVII-23, in general, T AS2 is comparable to Ah2, so that the entropy contribution to the free energy of adsorption is important. Notice in Figs. XVII-23 i and b how nearly the entropy plot is a mirror image of the enthalpy plot. As a consequence, the maxima and minima in the separate plots tend to cancel to give a smoothly varying free energy plot, that is, adsorption isotherm. 

Fig. 7.2. Calculated [40] relative ion population as a function of ion charge state in solid Ti heated at temperatures ranging from 10 to lOOeV. Also shown in the same plot is the separation energy of the 2p-ls transitions as a function of the ion charge. Higher ionization stages from B-like Ti to O-like Ti are expected to emit in the range between 4,550 and 4,750 eV...

The valence structure of argon provides a complete illustration of the application of electron momentum spectroscopy to correlations in the ion. The Hartree—Fock single-electron level diagram of fig. 11.1 illustrates the values of the separation energy e to be expected on the basis of the independent-electron model. The experimental situation is illustrated in fig. 11.2 by the first experiment in the field (Weigold, Hood and Teubner, 1973). The noncoplanar-symmetric differential cross section at 10° is plotted against Eq for =400 eV. There is an ion state at 15.76 eV, as predicted by Hartree—Fock, but there are at least two further states rather than the predicted one. 

FIGURE 6.8 Comparison of potential energy for the Ugi, and crJi, orbitals of Hj in the LCAO approximation (dashed lines) with the exact results (solid lines). The internudear separation is plotted in units of the Bohr radius. 

As examples of series of related reactions, compensation effects have been described [53] for the thermal decompositions of [CoXj (aromatic amine)2] type complexes (7 reactions) and also for a series of cobalt (III) and chromium (III) complexes (22 compounds studied in which two compensation trends were identified). Later work [54] examined the dehydrations and deamminations of dioximine complexes (two compensation trends identified), and [Co(NCS)2(ammine)2]-type complexes (three compensation trends identified). The systems involving larger entropy changes required less energy for activation [53]. Separate compensation plots for the dehydrations and the decompositions of eleven alkali and alkaline-earth metal dithionates were described by Zsako et al. [55]. 

Figure 6-2. Left Correlations between photo-induced hole transport rate constants and structural distances in synthetic capped hair-pin double-strand oligonucleotides for charge separation (open symbols) and charge recombination (filled symbols). Right Free energy plots for charge separation (filled symbols) and recombination (open symbols) Circles and triangles represent different sensitizer molecular units. Reprinted from ref. 52 with permission.

The activation energies obtained by last-squares calculation from separate Arrhenius plots for the two types of film showed that the apparent difference between the two values was beyond the limit of probable significance. Consequently, a least-squares calculation was made from the combined data, to give 15.8 1.3 kcal./mole for the range 125 to 189° (see Fig. 2). Recent investigations of the nickel-catalyzed decomposition by other workers have given values of 15 kcal./mole (10) and 20 kcal./mole 11,12). 

Figure 4 Variation of the (calculated) carbon-carbon bond lengths (A) in the butadiene portion of a variety of five-membered rings plotted against the bond separation energies (kcal/mol) of the ring species. The nine molecules are structures 3—9 plus cyclopentadiene and the cyclopentadienyl anion. The bond separation energies are defined with respect to an equation like Eq. [33].

Figure A10.9 The various terms in the electron-nuclear potential energy plotted as a function of Internuclear separation for (a) H2 in the ground state, with theelectron in 1

FIGURE 5.10 Relative importance of the three gamma effects in a Z versus energy plot. The lines separate zones for which probability for the neighbouring effects are equal. After figures from Baker Allas (1985) and Hearst and Nelson (1985). 

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