Description writing

This essay prompt provides you the freedom to choose between two kinds of writing informative paragraphs or descriptive writing, i.e., poetry which will produce the (sensory) images found in your typical day, rather than describe or explain them more formally. 

Zeroth-order description. Write down the matrix of the model space that only considers neutral determinants expressed in local orbitals. Diagonalize the matrix and calculate the singlet-triplet energy difference. What is the state of lowest energy ... 

Based on these descriptions, write a balanced equation and the corresponding expression for each reversible reaction. 

One of the most significant achievements of the twentieth century is the description of the quantum mechanical laws that govern the properties of matter. It is relatively easy to write down the Hamiltonian for interacting fennions. Obtaining a solution to the problem that is sufficient to make predictions is another matter. 

By analogy with Eq. (3.1), we seek a description for the relationship between stress and strain. The former is the shearing force per unit area, which we symbolize as as in Chap. 2. For shear strain we use the symbol y it is the rate of change of 7 that is involved in the definition of viscosity in Eq. (2.2). As in the analysis of tensile deformation, we write the strain AL/L, but this time AL is in the direction of the force, while L is at right angles to it. These quantities are shown in Fig. 3.6. It is convenient to describe the sample deformation in terms of the angle 6, also shown in Fig. 3.6. For distortion which is independent of time we continue to consider only the equilibrium behavior-stress and strain are proportional with proportionality constant G ... 

Scale-up and performance of a 1.47-m Scheibel column have been reported (98,154,155), as have detailed description and design criteria for the Scheibel column (156) and scale-up procedures (157). The same stage efficiency can be maintained on scale-up, and total throughput can be increased by three and one-half times at the expense of higher HETS. As of this writing, Scheibel columns up to 2.75 m in diameter are in service. 

Polymeric Ma.teria.Is, The single-ply membranes are made from a wide variety of polymers. The following is a brief description of those polymers and their characteristics. There are three thermosetting-type elastomeric membranes as of this writing (1996) neoprene, CSPE, and EPDM. Neoprene is stiU used where oil resistance is needed. Eor instance. Hydrotech uses neoprene flashings, the base of which is hot-set in mbberized asphalt (see ElASTOL RS, SYNTHETIC-POLYCm.OROPRENE). 

A thorough description of the internal flow stmcture inside a swid atomizer requires information on velocity and pressure distributions. Unfortunately, this information is still not completely available as of this writing (1996). Useful iasights on the boundary layer flow through the swid chamber are available (9—11). Because of the existence of an air core, the flow stmcture iaside a swid atomizer is difficult to analyze because it iavolves the solution of a free-surface problem. If the location and surface pressure of the Hquid boundary are known, however, the equations of motion of the Hquid phase can be appHed to reveal the detailed distributions of the pressure and velocity. 

IR and Raman studies of heterocycles today cover two different fields. For simple and symmetrical molecules very elaborate experiments (argon matrices, isotopic labelling) and complex calculations lead to the complete assignment of the fundamentals, tones and harmonics. However, the description of modes ought to be only approximate, since in a molecule like pyrazole there are no pure ones. This means that it is not correct to write that the band at 878 cm is y(CH), and the only correct assertion is that the y(CH) mode contributes to the band. On the other hand, IR spectroscopy is used as an analytical tool for identifying structures, and in this case, bands are assigned to r-iCO) or 5(NH) on the basis of a simple Nujol mull spectrum and conventional tables. Both atttitudes, almost antagonistic to each other, are discussed in this section. 

It is worth noting that in the case of the reactions of ediylene and butadiene with the allyl cation, the MO description has provided a prediction that would not have been recognized by a pictorial application of valence bond terminology. Thus, we can write an apparently satisfactory description of both reactions. 

Find a description of an innovative composite structure, device, or object in a publication such as Aviation Week and Space Technology, Mechanicai Engineering, Civii Engineering, etc. and write a synopsis of its important characteristics. 

An important issue in the writing of procedures is how much information is necessary for the process worker in order to minimize the likelihood of error. Too little may be inappropriate for an inexperienced process worker while too much may encourage a highly experienced worker not to use the procedure. It is obvious that the level of worker expertise and the criticality of the task will determine the level of description. This example shows how lack of detailed information can lead to errors of omission. 

The quantitative description of enzyme kinetics has been developed in great detail by applying the steady-state approximation to all intermediate forms of the enzyme. Some of the kinetic schemes are extremely complex, and even with the aid of the steady-state treatment the algebraic manipulations are formidable. Kineticists have, therefore, developed ingenious schemes for writing down the steady-state rate equations directly from the kinetic scheme without carrying out the intermediate algebra." -" ... 

An alternative deseription of these energetic effects has been given by Pross and Shaik. - Again the Sn reaction is used as an example. A valence bond (VB) description is developed by writing linear combinations of a basis set of configurations. These constitute a reasonable set of configurations (compare with Table 5-3) ... 

You are probably used to this idea from descriptive chemistry, where we build up the configurations for many-electron atoms in terms of atomic wavefunctions, and where we would write an electronic configuration for Ne as... 

We would normally write the electronic ground state electron configuration of a carbon atom as ls-2s 2p-. Despite the intellectual activity that has gone into defining mythical valence states for carbon atoms in different bonding situations, no one would include a d-orbital in the description of ground state carbon. 

Given the following descriptions of reversible reactions, write a balanced equation (simplest whole-number coefficients) and the equilibrium constant expression (X) for each. 

Some 20 years ago, I was privileged to share in writing a book on the descriptive chemistry of the 4d, 5d, 4f and 5f metals that included these eight elements within its compass (S.A. Cotton and F.A. Hart, The Heavy Transition Elements, Macmillan, 1975). This volume shares the same aim of covering the descriptive chemistry of silver, gold and the six platinum metals in some detail at a level suitable for advanced undergraduate and postgraduate study. 

The approach discussed above can provide a qualitative description of the effect of external fields on bond-breaking processes. For example, consider the H2 molecule (HA — HB) in the presence of an Li+ ion 3 A away from HB on the A-B axis. To study this problem, we assume that there is no charge migration to the Li location (so that Pc = 0) and that fiAC = pBC = 0 since the Li+ ion is sufficiently far from HA and HB. In this case, we can write the H matrix as... 

Sometimes we need to construct a balanced chemical equation from the description of a reaction. For example, methane, CH4, is the principal ingredient of natural gas (Fig. H.3). It burns in oxygen to form carbon dioxide and water, both formed initially as gases. To write the balanced equation for the reaction, we first write the skeletal equation ... 

However, as we shall shortly see, the two descriptions correspond to the direction in which we write the cell reaction and, therefore, to different signs used to report the cell emf. 

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