Monatomic ions properties

The solvation of polyatomic ions or polar neutral molecules is even more difficult to describe. There are two sources of additional problems first of all, the symmetry of the system under investigation is drastically reduced and hence the number of different configurations increases tremendously. Furthermore, the strength of the electric field is much smaller than in the case of monatomic ions with spherical symmetry and therefore the dynamic behavior of the solvation shell is even more important for a priori calculations of macroscopic properties. 

To turn now to crystals composed of4 unattached atoms or monatomic ions, which ar6 individually isotropic. Here it is only the second factor —the effect of arrangement—which can be responsible for anisotropy in the crystal. It is the orderliness of arrangement itself which, because it gives rise to different atomic distributions in different directions (Fig. 2 c), confers properties varying with crystal direction. The degree of anisotropy is usually far less in these crystals than in crystals containing molecules or polyatomic ions which are themselves anisotropic. 

THE ZEEMAN EFFECT AND THE MAGNETIC PROPERTIES OF ATOMS AND MONATOMIC IONS... 

When an atom loses or gains electrons, it forms a monatomic ion, an ion from a single atom. (All the ions described in this section are monatomic ions.) The chemical properties of an ion are not at all like those of the atom from which it came the electrical charge becomes the dominant property. A sodium atom, Na, and a sodium ion, Na+, are chemically very different. Sodium atoms could never exist in contact with water, for example, because they react vigorously with water, but sodium ions exist in water without a problem. 

Answer (b) O and 10 are both neutral isotopes of oxygen and have the same chemical properties. The other pairs are also isotopes of one another, but in each case, one is neutral and the other an ion. Monatomic ions are not similar chemically to neutral atoms of the same element. 

It is generally believed that the polarizabilities of monatomic ions and molecules are independent of field direction. For undistorted quasi-spherical molecules (e.g. CH4, CC14, etc.) the same is usually assumed. When two such atoms are held together, as in a diatomic molecule, the new system is not isotropically polarizable. The model discussed by Silberstein (1917) makes this understandable. If a unit field acts along the line of centres A-B it will induce primary moments parallel to itself in both A and B, and likewise if it acts at 90° to A-B. Each primary moment will induce a secondary moment in its neighbour in the first case the secondary moments will add to the primary moments, but in the second they will subtract. Hence b along the line of centres exceeds that across it, and the polarizability of A-B is an anisotropic property. A similar situation is to be expected with the majority of polyatomic ions or molecules (see Table 21). 

Trends in Metallic Behavior Properties of Monatomic Ions... 

In 1965 Edgell and co-workers reported an infrared band, from solutions of alkali metal salts of Co CO) dissolved in tetrahydrofuran (THF), which was assigned to the cation vibrating in a solvent cage. Subsequently a detailed report about the nature of the vibration of these monatomic ions in several non-aqueous solvents was given. The bands are broad and of medium intensity. Thus their properties are... 

Frank and Robinson (1940) suggested that the partial molar entropy of the water in aqueous electrolyte solutions is affected by the structure-making or -breaking properties of their ions. Frank and Evans (1945) suggested that rather the entropies of hydration of the ions shed light on these properties. Gurney (1953) showed that a linear relationship exists between the partial molar entropy of monatomic ions, and their viscosity coefficients (see Sect. 3.1.1). Nightingale (1959) reverted to the Frank and Evans emphasize of partial molar entropies of hydration of the... 

Trends in Metallic Behavior 265 Properties of Monatomic Ions 266 CHAPTER REVIEW GUIDE 271 PROBLEMS 272... 

The thing that makes the periodic table so helpful in writing chemical formulas is that all the elements in Group 2A/2 that form monatomic ions do so by losing two electrons. This loss of two electrons gives the elements of Group 2A/2 their similar chemical properties. 

The tin(II) and lead(II) ions, Sn + and Pb +, behave like other monatomic ions. Tin and lead in compounds in which the elements appear to have 4+ charges have properties that differ from the properties of other compounds made up of ions. This notwithstanding, the compounds are named as if they were made up of true ions. 

The solvation shells of ions may not be spherically symmetrical, a phenomenon that occurs at the surfaces of solutions. The solvent molecules may then polarize the ions, even if they are monatomic, and thus affect their properties. However, in the bulk of the solutions, monatomic ions reside in a spherically symmetrical field and are themselves little affected by the solvent. This is not necessarily the case for polyatomic ions, even for those that have a globular shape. This effect is most noted in the vibrational and rotational relaxation times of polyatomic ions. The relaxation is measurable by the pump/probe technique, where the laser beam at the wave-number of the ground state is followed after a short interval by a probe beam at the level of the excited state, following its exponential decay. 

In this article, we present a brief outline of the methods used and introduce the structural properties which can be calculated directly from the experimental data. Several examples have been selected to demonstrate the power of these methods, with reference to studies of monatomic ions such as Ni + and Cl (Figs. 1-3). We also mention an extension to the NDIS method that applies to aqueous solutions of null water and enables one to determine the nearest neighbour coordination of strong cations for cations which do not possess isotopes suitable for the NDIS method. ... 

The periodic table helps chemists describe and predict the properties of chemical compounds and the outcomes of chemical reactions. Throughout this text, we will use it as an aid to understanding chemical concepts. One application of the table worth mentioning here is how it can be used to predict likely charges on simple monatomic ions. 

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