Square brackets, use

The relative contributions of each type of interaction to the total van der Waals interaction has been determined by Israelachvili [95] for pairs of similar and dissimilar molecules theoretically by comparing the magnitudes of the terms within the square brackets, using reported values for the polarizability and the ionization potential of these molecules. These results are summarized in Table 1. 

No numerical subscript should follow the square bracket used in this context. For example, where the molecular formula is double the empirical formula, this should be indicated inside the square bracket. 

For more details on crysfol chemical formulae, peuticulaiy for the meaning of the symbols and the commas, semi-colons and small letters within the superscripted square brackets used in the crystal chemical formulae, see the contribution of Uma-de-Faria in this book. 

The square brackets used in the expression for fQ indicate concentration, at equilibrium, of the enclosed species in moles per hter. The acidity constant is related to the equilibrium constant for the reaction shown in eq. 7.3 only the concentration of water [H2O] is omitted from the denominator of the expression since it remains nearly constant at 55.5 M, very large compared to the concentrations of the other three species. For a discussion of reaction equilibria and equilibrium constants, see Section 3.11. 

Atoms Atoms a e represented by their atomic symbols. Ambiguous two-letter symbols (e.g., Nb is not NB) have to be written in square brackets. Otherwise, no further letters are used. Free valences are saturated with hydrogen atoms. 

In order to describe the number of primitives and contractions more directly, the notation (6s,5p) (ls,3p) or (6s,5p)/(ls,3p) is sometimes used. This example indicates that six s primitives and hve p primitives are contracted into one s contraction and three p contractions. Thus, this might be a description of the 6—311G basis set. However, this notation is not precise enough to tell whether the three p contractions consist of three, one, and one primitives or two, two, and one primitives. The notation (6,311) or (6,221) is used to distinguish these cases. Some authors use round parentheses ( ) to denote the number of primitives and square brackets [ ] to denote the number of contractions. 

Molar concentrations are used so frequently that a symbolic notation is often used to simplify its expression in equations and writing. The use of square brackets around a species indicates that we are referring to that species molar concentration. Thus, [Na ] is read as the molar concentration of sodium ions. ... 

The rate of a process is expressed by the derivative of a concentration (square brackets) with respect to time, d[ ]/dt. If the concentration of a reaction product is used, this quantity is positive if a reactant is used, it is negative and a minus sign must be included. Also, each derivative d[ ]/dt should be divided by the coefficient of that component in the chemical equation which describes the reaction so that a single rate is described, whichever component in the reaction is used to monitor it. A rate law describes the rate of a reaction as the product of a constant k, called the rate constant, and various concentrations, each raised to specific powers. The power of an individual concentration term in a rate law is called the order with respect to that component, and the sum of the exponents of all concentration terms gives the overall order of the reaction. Thus in the rate law Rate = k[X] [Y], the reaction is first order in X, second order in Y, and third order overall. 

Fig. 4. Example of international patent classification (stmctured, hierarchical), where numbers ia square brackets identify edition of IPC ia which class was first used. In C07c 45/50, the first four characters iadicate section C (chemistry). Class 07 (organic chemistry), and subclass c (acycHc compounds) the number 45 /00 iadicates the preparation of compounds having carbonyl groups bound only to carbon or hydrogen atoms by any method and 45 /50...

The terms in square brackets are to do with the nuclear motion the first two of these represent the kinetic energy of the nuclei labelled A and B (each of mass M), and the third term in the square brackets is the Coulomb repulsion between the two nuclei. The fourth and fifth terms give the kinetic energy of the two electrons. The next four negative terms give the mutual Coulomb attraction between the two nuclei A, B and the two eleetrons labelled 1, 2. The final term is the Coulomb repulsion between electrons 1 and 2, with rn the distance between them. As in Chapter 3, I have used the subscript tot to mean nuclear plus electron. 

Hereafter, we shall regularly use the square brackets notation, [ ], to indicate concentration. Thus, we read [Fe+I] as ferric ion concentration. ... 

Square brackets are commonly used for two purposes to denote concentrations and also to include the whole of a complex ion for the latter purpose curly brackets (braces) are sometimes used. With careful scrutiny there should be no confusion regarding the sense in which the square brackets are used with complexes there will be no charge signs inside the brackets. 

Generally one uses square brackets to indicate that the formula-weight of the substance, the symbol of which they enclose, is taken in the solid state, round brackets to show that it is in the gaseous state, and no brackets when it is liquid.)... 

Square brackets in kinetic equations signify the effective concentrations of the bracketed species, these being the equilibrium forms actually taking part in the rate-determining step. Parentheses are used for stoichiometric concentrations. Thus (ArNH2) is the total amount of an amine present in the system, even if it... 

Square brackets are commonly used to indicate the presence of a d-metal complex. 

When dealing with the kinetic or thermodynamic behaviour of transition-metal systems, square brackets are used to denote concentrations of solution species. In the interests of simplicity, solvent molecules are frequently omitted (as are the square brackets around complex species). The reaction (1.1) is frequently written as equation (1.2). 

Notice that square brackets are used in a new way for the silver-ammonia complex in the chemical reaction. Chemists use square brackets to identify a complex ion such as [Ag (NH3)2, because the species involved in... 

To determine the electron configuration in this manner, start with the noble gas of the previous period and use the subshell notation from only the period of the required element. Thus, for Fe, the notation for Ar (the previous noble gas) is included in the square brackets, and the 4s23db is obtained across the fourth period. It is suggested that you do not use this notation until you have mastered the full notation. Also, on examinations, use the full notation unless the question or the instructor indicates that the shortened notation is acceptable. 

The quantity in square brackets which is a function only of k [fn (k)], represents the dependence of the flow rate on the gas property. Hence it can be used to define a correction factor C2 that can be used as a multiplier to correct the flow rate for air to that for any other gas ... 

By definition, a numerical matrix is a rectangular array of numbers (termed elements ) enclosed by square brackets [ ]. Matrices can be used to organize information such as size versus cost in a grocery department, or they may be used to simplify the problems associated with systems or groups of linear equations. Later in this chapter we will introduce the operations involved for linear equations (see Table 2-1 for common symbols used). 

Bq/m3) thoron progeny Working Level, WL(Tn) 0.15-14 WL. (The square brackets are used here to denote activity concentration.)... 

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