Refraction, atomic organic molecules

In view of this, it is not surprising that neighbouring ions have only minor effects, since the distances between oxygen atoms in neighbouring ions are 2-7 A. Nor is it surprising that in crystals in organic substances, where the distances between linked carbon atoms are 1 3-1 5 A and the distances between carbon atoms in neighbouring molecules 3 5-4 2 A, the refractive indices depend almost entirely on the refractivities of individual molecules and the relative orientations of these molecules in the crystals. 

A substance is said to be chemically pure when it is made up of identical atoms and molecules. This means that the concept of purity can only apply to a single element or compound. As essential oils are made up of mixtures of organic compounds, they cannot be strictly chemically pure. Chemical purity and composition have to be related to an odour profile and be free from any contamination. Standard samples are used for reference when considering the purity of an essential oil, and the analytical techniques of GC-MS, refractive index and other methods previously described are applied. A standard sample or standard oil is a sample of a product that conforms to a specification for that product. It is kept for purposes of comparison with batch samples and used in quality evaluation. 

Effect of the fluorine atom on the molecular orbital energy levels of organic molecules and refractive index... 

This section discusses how the fluorine atom influences the physical and physicochemical properties of organic fluorine compounds. One of the most important factors for a better understanding of such properties would be the low electronic polarizability (refractive index) of the molecules. Of course, we cannot disregard other effects such as the strong electron-withdrawing effect and stiff nature of the perfluoroalkyl moiety. 

Rather than develop a separate set of parameter values for each organic solvent, SM5.0R takes each surface tension coefficient af and tjij to depend on certain properties of the solvent such as its index of refraction, surface tension, and fraction of nonhydrogen atoms in the solvent molecule that are aromatic carbons, and to depend on parameters many of whose values depend on the nature of atom i or atoms / and j (whether they are H, C, N,... ) but whose values are the same for every oi anic solvent. The values of the parameters are fitted using a training set of 1836 AG i, values for 227 uncharged solutes in 90 organic solvents. 

Physical Properties. Physical properties include density, properties connected to their combustion tendency (flammability and oxygen index), optical properties (refractive index and yellow index), and the ability to absorb water. Density p, ie, the mass per unit volume, depends on the nature of atoms present in the chemical structure and the way molecules (chains) pack together. Polyoleflns, composed of C and H only, have densities in the range 0.85-1 organic polymers... 

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