Matter bulk, ordinary

Because a bulk sample of matter is electrically neutral, ionic compounds always contain both cations (positively charged particles) and anions (negatively charged particles). Ordinary table salt, sodium chloride, is made up of an equal number of Na+ and Cl- ions. The structure of sodium chloride is shown in Figure 2.11. Notice that—... 

Whether they are called surfaces or interfaces, when the zones between parts of a structure are "thin"— from a fraction of a micrometer (the limit of the ordinary microscope) down to molecular dimensions—the matter in them assumes a character that is somewhat different from that seen when the same matter is in bulk form. This special character of a molecular population arranged as an interfacial zone is manifested in such phenomena as surface tension, surface electronic states, surface reactivity, and the ubiquitous phenomena of surface adsorption and segregation. And the stmcturing of multiple interfaces may be so fine that no part of the resulting material has properties characteristic of any bulk material the whole is exclusively made up of transition zones of one kind or another. 

Marcos Boll has shown that, for every fifty-six ports of actual wood contained in an ordinary stack, there are forty-four of unoccupied space. In prosecuting his inquiries into this snbjcct, he determined the real amount of matter in a given bulk of wood, the tabulated specific gravity having been previously ascertained by coating the wood with varnish as already stated... 

The large clusters are essentially small particles of bulk matter. Their properties vary little with size. They differ from ordinary bulk matter primarily in having large surface areas and enough curvature of those surfaces to make their equilibrium vapor pressures and other related properties a bit different from those of macroscopic samples of the same materials. 

We must differentiate between bulk flow and molecular flow. If in the capillary would be a movable plunger or barrier, then the subsystem with the lower pressure would expand at the cost of the other system. However, this process will occur even when there is no barrier. The subsystem moves into the area of the other subsystem. If there is a membrane, not permeable to the flow of entropy, but permeable to matter, then the subsystem will exert to the other system a pressure, but no flow will occur. The situation is similar to that of osmosis. However, when matter moves, it carries entropy. So, under ordinary conditions, it is difficult or impossible to fabricate such a membrane. 

Ordinary liquids and liquid crystals are nearly incompressible. In ordinary fluid dynamics the incompressibility approximation under the constraint div v = 0 has frequently been utilized. In a soft elastomer such as vulcanized rubber, where shear modulus is very small as compared with bulk modulus, the incompressibility approximation has also been usefully employed. The constraint of the incompressibility approximation, div v = 0 for ordinary fluids or divergence of displacement vector for elastic (isotropic) materials, does not modify any other terms of the equations of motion div v = 0, or divergence of displacement vector, is a solutirai of the equations of motion, provided that pressure p is chosen as an appropriate harmoiuc function (V p = 0). However, for anisotropic matters, such as liquid crystals or anisotropic solids (crystals), since the div v = 0 or its elastic version cannot be a special solution of equations of motion, the incompressibility approximation requires a careful consideration [12, 18]. 

The same sort of treatment as for ordinary metallic bulk matter can also be applied to surface core-level shifts. The surface atoms experience a different potential compared to the layers below because of the lower coordination number. This results in somewhat different core level binding energies. One can extend the previous Born-Haber cycle model to account for the surface-bulk core level shift. Empirically, the surface cohesive energy is approximately 80% of the bulk value. The impurity term can then be written as... 

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