Anomalous properties

Another anomalous property of some nickel—iron aHoys, which are caHed constant-modulus aHoys, is a positive thermoelastic coefficient which occurs in aHoys having 27—43 wt % nickel. The elastic moduH in these aHoys increase with temperature. UsuaHy, and with additions of chromium, molybdenum, titanium, or aluminum, the constant-modulus aHoys are used in precision weighing machines, measuring devices, and osciHating mechanisms (see Weighing AND proportioning). 

Both in work reviewed herein and in theoretical research by other workers[10-30], a consensus has been reached that anomalous properties (compared to graphite and normal graphitic nanotubes) can be obtained with graphitic nanotubes with diameters of the order of a nanometer. In terms of electronic properties, the nanotubes are expected to fall into two major classes on one hand the moderate band gap nanotubes that do not satisfy the Wj — = 3 /w condition in the... 

POLITZER, Anomalous properties of fluorine, J. Am. Chem. Soc. 91, 6235-7 (1969) Some anomalous properties of oxygen and nitrogen, Inorg. Chem. 16, 3350-1 (1977). 

More comprehensive examination of speetroseopie and magnetic properties of d ions followed which provided an explanation for the different types of Lifsehitz salts (p. 1160) and led to studies of systems exhibiting anomalous properties. Rational explanations of these properties were eventually forthcoming. 

The halogens show smooth trends in chemical properties down the group fluorine has some anomalous properties, such as its strength as an oxidizing agent and the lower solubilities of most fluorides. 

Silver iodide also has other anomalous properties it is physically soft - it can even be beaten into a sheet, unlike the overwhelming majority of ionic compounds. More unusual still, it is slightly soluble in ethanol. Clearly, silver iodide is not a straightforward ionic compound. In fact, its properties appear to overlap between covalent (see Table 2.6) and ionic (see Table 2.7). 

The anomalous properties of water remain an important subject of inquiry (Errington and Debenedetti, 2001 Mishima and Stanley, 1998). Chaplin (2004) gives a comprehensive overview of 40 anomalous properties of water and suggested explanations. Chaplin (2004) aptly pointed out that whether the properties of water are viewed as anomalous depends on what materials water is compared to and the interpretation of the term anomalous. For example, Angell (2001) included a section on the nonuniqueness of water, stating that. . water is not unique, as is often supposed, but rather water is an intermediate member of a series of substances that form tetrahedral networks of different degrees of flexibility, and that, accordingly, show systematic differences of behavior. Additional references that discuss the properties of water as nonanomalous are Franks (2000), Kivelson and Tarjus (2001), and Netz et al. (2002). 

Ludwig s (2001) review discusses water clusters and water cluster models. One of the water clusters discussed by Ludwig is the icosahedral cluster developed by Chaplin (1999). A fluctuating network of water molecules, with local icosahedral symmetry, was proposed by Chaplin (1999) it contains, when complete, 280 fully hydrogen-bonded water molecules. This structure allows explanation of a number of the anomalous properties of water, including its temperature-density and pressure-viscosity behaviors, the radial distribution pattern, the change in water properties on supercooling, and the solvation properties of ions, hydrophobic molecules, carbohydrates, and macromolecules (Chaplin, 1999, 2001, 2004). 

Early In this century there was great interest in the apparently anomalous properties of aqueous electrolytes. The anomaly concerned the limiting behavior at low concentration. 

Vitreous Silica Vitreous sdica is a glass form of sdica composed of Si02. It may be transparent, translucent, or opaque. It has a number of abnormal and anomalous properties in thermal expansion, viscosity, bulk density, compressibility, and elasticity. These properties depend on thermal history and preparation method. Vitreous sdica exhibits high resistance to chemical attack. At ambient temperature, it is not attacked by any chemical except hydrofluoric acid. 

The crystal chemistry of the H ion is so anomalous that it is usually considered to be qualitatively different from other cations, yet its anomalous properties can be derived in a perfectly rational way by assuming that H is, in principle, no different from other cations except for its small size. H" " is the only cation where the anion-anion repulsion predicts a maximum regular coordination number of less than 2, as can be seen in Fig. 6.4, where the point for regular two-coordinate H ( = 0.5 vu) lies well to the left of the line. However, as... 

The dipole moments of CO and NO are 0.1 D and 0.166 D. respectively. The oxygen atom is the positive end of the CO dipole, despite the difference in electronegativity coefficients of the two atoms which would imply the opposite conclusion. Consider the electronic configurations of the two molecules, and explain the anomalous properties of the CO molecule. 

That the molecules in solid and liquid water interact by hydrogen bonding and that hydrogen bonding is responsible for the anomalous properties of water compared with the other hydrides of Group 16... 

Although water is an excellent solvent and the most popular, it has somewhat anomalous properties that come from the hydrogen bonding ability of water to form three-dimensional networks (Fig. 1.2, Section 1.1.3). Large molecules and ions are often difficult to dissolve in water, unless they have hydrophilic site(s). Therefore, water is not suitable as a medium for reactions involving large hydro-phobic molecules or ions. In contrast, most dipolar aprotic solvents are non-struc-tured or only weakly structured and can dissolve many large molecules and ions. This is another major reason why dipolar aprotic solvents are often used instead of water. 

Gold s position in the Periodic Table is such that relativistic effects are at a maximum, and it has been argued convincingly that many of the anomalous properties of Au, when compared to Ag and Cu, may be ascribed to such effects. The relativistic effect is to strongly stabilize the 6s level, to stabilize the 6p levels to a lesser extent and to destabilize the 5d levels of gold. The effects are as follows ... 

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