The Solid State Types of Solids

Solids play a very important role in our lives. The concrete we drive on, the trees that shade us, the windows we look through, the paper that holds this print, the diamond in an engagement ring, and the plastic lenses in eyeglasses are all important solids. Most solids, such as wood, paper, and glass, contain mixtures of various components. However, some natural solids, such as diamonds and table salt, are nearly pure substances. 

There are many different types of crystalline solids. For example, both sugar and salt have beautiful crystals that we can easily see. However, although both dissolve readily in water, the properties of the resulting solutions are quite different. The salt solution readily conducts an electric current the sugar solution does not. 

This behavior arises from the different natures of the components in these two solids. Common salt, NaCl, is an ionic solid that contains Na and Cl ions. When solid sodium chloride dissolves in water, sodium ions and chloride ions are distributed throughout the resulting solution. These ions are free to move through the solution to conduct an electric current. Table sugar (sucrose), on the other hand, is composed of neutral molecules that are dispersed throughout the water when the solid dissolves. No ions are present, and the resulting solution does not conduct electricity. These examples illustrate two important types of crystalline solids ionic solids, represented by sodium chloride and molecular solids, represented by sucrose. 

The regular arrangement of sodium and chloride ions in sodium chloride, a crystalline solid 

We have seen that crystalline solids can be grouped conveniently into three classes. 

Example 13.3 Using Knowledge of Intermolecular Forces to Predict 

Predict which substance in each of the following pairs will show the largest vapor pressure at a given temperature. 

I AIM To learn about the various types of crystalline solids. 

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Dislocation theory as a portion of the subject of solid-state physics is somewhat beyond the scope of this book, but it is desirable to examine the subject briefly in terms of its implications in surface chemistry. Perhaps the most elementary type of defect is that of an extra or interstitial atom—Frenkel defect [110]—or a missing atom or vacancy—Schottky defect [111]. Such point defects play an important role in the treatment of diffusion and electrical conductivities in solids and the solubility of a salt in the host lattice of another or different valence type [112]. Point defects have a thermodynamic basis for their existence in terms of the energy and entropy of their formation, the situation is similar to the formation of isolated holes and erratic atoms on a surface. Dislocations, on the other hand, may be viewed as an organized concentration of point defects they are lattice defects and play an important role in the mechanism of the plastic deformation of solids. Lattice defects or dislocations are not thermodynamic in the sense of the point defects their formation is intimately connected with the mechanism of nucleation and crystal growth (see Section IX-4), and they constitute an important source of surface imperfection. 

Although the continuous-countercurrent type of operation has found limited application in the removal of gaseous pollutants from process streams (Tor example, the removal of carbon dioxide and sulfur compounds such as hydrogen sulfide and carbonyl sulfide), by far the most common type of operation presently in use is the fixed-bed adsorber. The relatively high cost of continuously transporting solid particles as required in steady-state operations makes fixed-bed adsorption an attractive, economical alternative. If intermittent or batch operation is practical, a simple one-bed system, cycling alternately between the adsorption and regeneration phases, 1 suffice. 

In the steady-state operation of the OXITOX reactor, pelletized solid of catalytieally aetivated sodium earbonate slides down a Silo type reaetor. Counter-current to the solid flow, the polluted air rises through the sliding bed of solids. At reaction temperature the following reaetion oecurs ... 

Advances in laser technology now allow for solid-state lasers of high beam quality. These beams may be projected from a much smaller auxiliary telescope, which negates the need for optical switching and completely eliminates any main telescope fluorescence. Solid-state YAG lasers are the most common type of lasers commercially available. These lasers use a crystal as the lasing... 

A solution is a mixture of two or more substances. The substances involved are mixed so intimately (on the atomic scale) that it is not possible to distinguish their individual properties. A solution constitutes a single phase, as distinct from heterogeneous systems which contain several phases. A solution, however, differs from a chemical compound in that its composition is not fixed but can vary over a range. It is customary to designate the major component of a solution as the solvent, and the minor ones as the solutes. A solvent as well as a solute can be a gas, a solid or a liquid. Depending upon the state of the solute and/or the solvent, several types of solutions may exist. 

There are numerous variations on the basic linear structure of polymers. Returning to our example of polyethylene, we find short chain branches and long chain branches, as shown in Figs. 1.2 and 1.3, respectively. The number and type of these branches strongly influences the way that the molecules pack in the solid state, and hence affect the physical properties. Long... 

In this chapter we discussed the three basic types of solid state structure that we find in polymers and how they form from the molten state. We went on to describe the techniques that polymer scientists use to characterize polymer structures at scales ranging from less than one nanometer (1 X 10"9 m) up to a few millimeters (> 1 x 1CT3 m). The wide range of structures that we can generate from polymers contributes to their wide range of properties and corresponding breadth of finished items that we can create. 

Uterine leiomyomas, or fibroids, are the most common type of solid tumors in adult women, clinically apparent in at least 25% of those of reproductive age [24-26]. Abnormal menstrual bleeding, pelvic pain, and infertility are the most commonly experienced symptoms in these women. Uterine fibroids are the leading cause of hysterectomies performed in the United States, accounting for over 200,000 of these procedures each year. Other invasive surgical interventions for the treatment of uterine fibroids include myomectomy and uterine artery embolization. Leiomyomas are estrogen-responsive tumors that can be treated... 

Metastable crystalline phases frequently crystallise to a more stable phase in accordance with Ostwald s rule of stages, and the more common types of phase transformation that occur in crystallising and precipitating systems include those between polymorphs and solvates. Transformations can occur in the solid state, particularly at temperatures near the melting point of the crystalline solid, and because of the intervention of a solvent. A stable phase has a lower solubility than a metastable phase, as indicated by the solubility curves in Figures 15.7a and 15.7/ for enantiotropic and monotropic systems respectively and,... 

At this time the only commercially available all-solid-state cell is the lithium battery containing Lil as the electrolyte. Many types of solid lithium ion conductors including inorganic crystalline and glassy materials as well as polymer electrolytes have been proposed as separators in lithium batteries. These are described in the previous chapters. A suitable solid electrolyte for lithium batteries should have the properties... 

The chemical shift 5, defined by Equation (22), was measured at 40.0 and 15.6 Mc./sec. and was found to be —3 2 relative to water for both SA and SG. The derivatives of the resonance absorptions were recorded in the measurements. If the total anisotropy of the chemical shift of protons in the solid is somewhat less than the line width, the cross-over point of the derivative will correspond to the average value of S as for liquids, and will be directly comparable with the shifts for protons in the liquid state. Comparison of the shift value with those of H3O+ (aqueous) (1 1), S = -1-11, OH (aqueous) (121), S = -1-10 dilute solutions of alcoholic-type protons... 

In addition to the topics we cover in this book, you can find even more information online. The Cheat Sheet at www.dummies. com/cheatsheet/chemistrywb provides some quick and useful tips for solving the most common types of chemistry problems you ll see. If you d like to pick up some chemistry-specific study tips, find out more about solid-state chemistry, or see a valuable alternative to determining concentration in molcirity, go to WWW.dummies.com/extras/chemistrywb. 

The basic parameters which determine the kinetics of internal oxidation processes are 1) alloy composition (in terms of the mole fraction = (1 NA)), 2) the number and type of compounds or solid solutions (structure, phase field width) which exist in the ternary A-B-0 system, 3) the Gibbs energies of formation and the component chemical potentials of the phases involved, and last but not least, 4) the individual mobilities of the components in both the metal alloy and the product determine the (quasi-steady state) reaction path and thus the kinetics. A complete set of the parameters necessary for the quantitative treatment of internal oxidation kinetics is normally not at hand. Nevertheless, a predictive phenomenological theory will be outlined. 

The chemical microstructures of cis-polyisoprene (HR) vulcanised with sulfur and N-t-butyl-2-benzothiazole sulfenamide (TBBS) accelerator were studied as a function of extent of cure and accelerator to sulfur ratio in the formulations by solid-state 13C NMR spectroscopy at 75.5 MHz [29]. Conventional (TBBS/Sulfur=0.75/2.38), semi-efficient (SEV=1.50/1.50) and efficient (EV=3.00/1.08) vulcanisation formulations were prepared, which were cured to different cure states according to the magnitude of increase in rheometer torque. The order and types of the sulfurisation products formed are constant in all the formulation systems with different accelerator to sulfur ratios. However, the amount of sulfurisation has been found to vary directly with the concentration of elemental sulfur. 

Three of the four presumed types of chemical bond that occurs in the solid state have been reduced to the common basis of interaction between opposite charges localized at crystallographic lattice sites, apparently at variance with the pairwise covalency described before. 

Although there are very few documented examples of solid-state reactions that proceed with high control and that occur by phase-separation mechanisms, it is likely that this will prove to be the most common type of solid-to-solid reaction. A few examples from the literature are described below. 

We have illustrated the methods to obtain solid state selection rules. It should be mentioned that tables for factor group or point group analyses have been prepared by Adams and Newton (56,57) where one can read the number and type of species allowed directly from the table. Although useful, the approach neglects the procedures as how to obtain results in the tables. For further examples of the correlation method, see Refs. 58-61, and the Correlation Theory Bibliography. 

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