Weight, defined

Atomic Weight. As of this writing (ca 1994) the definition of atomic weights is based on carbon-12 [7440-44-0], the most abundant isotope of carbon, which has an atomic weight defined as exactiy 12 (21). 

MWR = is used, where Af is a melt-viscosity-average molecular weight defined by the equation Af = antilog, (0.493 log Tf + 3.5576, where Tj is... 

For some purposes this average may be less useful than the weight average molecular weight defined by which considers the fraction by weight of each molecular size i.e. 

Figure 1. a) Quantum graph b) periodic path on a graph with quantum weights defined with respect to the line - graph. 

Isotopes answer a puzzle that troubled chemists ever since Dalton proposed his atomic theory. Dalton said that the key property of an atom is not its size or shape but its weight. Each element is characterized by an atomic weight defined relative to that of hydrogen. The fact that these relative atomic weights were usually... 

To this end, branching has been determined conventionally in dilute solution by the ratio of intrinsic viscosities of branched and linear polymers having the same molecular weight, defined by (3) ... 

These two types of molecular weight averages are representative of the type called absolute methods, in that well-established thermodynamic equations can be used to convert the experimental data directly into a value of the molecular weight. However, some other methods require calibration. The most important of these indirect methods involves a measurement of the intrinsic viscosity. This quantity is a measure of the extent to which a polymer molecule increases the viscosity of the solvent in which it is dissolved. The viscosity method can be calibrated to yield a viscosity-average molecular weight, defined by... 

While the unprojected weighting defined by Equation (16) can be written (for a solution of rigid molecules) in terms of explicit components of the mode eigenvectors as... 

Table W8 Bond weights defined according to Z, X, Y, A, P, R, and E weighting schemes.

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