Scale of things

The chemist must learn to live in, and to feel at home in, the world of molecules. It is not enough that he knows the chemical constitution and chemical reactions of the materials around him. To be really effective and successful, he must also develop an intimacy with the molecular world. He must fit himself into the molecular scale of things. He must put that first drummed-in chemical fact that molecules are small in the very back of his mind and replace it by a consciousness that molecules are real, intricate, structural arrangements of atoms in space. 

Fig. 1.1 Overview of natural and synthetic nanoscale materials in context of micro- and macroworld, as well as the atomic scale. Source Department of Energy Office of Basic Energy Sciences. Detailed figure available at http //www.sc.doe.gov/bes/scale of things.html...

Now consider some numbers to get a feeling for the scale of things and for when to include phase changes. The properties of three interesting materials are listed in Table I. 

Scale of Things, In Meters. Lower Scale Continues in the Upper Bar from Left and Right.4-16... 

This section describes the use of separation processes which utilize membranes. Placement in this chapter is in recognition of the recent ascendency of industrial-scale rnernbrane-based separations, but it also reflects the iew that within a decade, many of these separation processes will be mainstream unit operations. Some approach that status already. Figure 22-46 shows the relath e size of things important in membrane separations. 

Heisenberg s uncertainty principle forced a change in thinking about how to describe the universe, hi a universe subject to uncertainty, many things cannot be measured exactly, and it is never possible to predict with certainty exactly what will occur next. This uncertainty has become accepted as a fundamental feature of the universe at the scale of electrons, protons, and neutrons. 

Object abstraction gives us the ability to treat a whole collection of objects—people, hardware, software, or a mixture—as a single thing with a definable behavior. This can be applied on the large scale of complete computer systems and businesses or on the small scale such as software sets and lists. 

Those things which are common/standard for all entries on the form should he stated as such once. These could include such things as instrument used, scale of measurement (°C, F, or K), or the location where the recording is made. 

Assess the essay you wrote for the practice exercise in Lesson 19. On a scale of 1-5, how would you rate your essay What are its strengths What are its weaknesses Identify the things you did well in your essay. Then, list the ways you think your essay could be improved. 

Note that I do not say infinitely small , for there are things smaller than atomic nuclei, namely elementary particles. There are also things larger than the astronomical scale of stars and galaxies that concerns us here. 

The scale of the operation itself leads to the need for large capital investments. Chemical reactors and plants are big and hence expensive because amongst other things the reactions don t go fast enough. If the reactions could be speeded up then the size of the plant could be reduced. Catalysts and catalysis are therefore a key area of fundamental chemistry for the energy field. 

As an indication of things to come, a year ago IFF in Paris revealed that it had just launched a commercial process based on ionic liquids that are available for licensing. The Difasol process for dimerizing butenes to isooctenes was developed at Rueil-Malmaison, and pilot-scale trials were carried out at IFP s pilot facilities at the Industrial Research Development Center at Solaize, near Lyon. 

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