Elements and Ions

Where to find rules for naming inorganic substances in this book. 

Common names are arbitrary names that are not based on the chemical composition of compounds. Before chemistry was systematized, a substance was given a name that generally associated it with one of its outstanding physical or chemical properties. For example, quicksilver is a common name for mercury, and nitrous oxide (N2O), used as an anesthetic in dentistry, has been called laughing gas because it induces laughter when inhaled. Water and ammonia are also common names because neither provides any information about the chemical composition of the compounds. If every substance were assigned a common name, the amount of memorization required to learn over 12 million names would be astronomical. 

Common names have distinct limitations, but they remain in frequent use. Common names continue to be used because the systematic name is too long or too technical for everyday use. For example, calcium oxide (CaO) is called lime by plasterers photographers refer to hypo rather than sodium thiosulfate (Na2S203) and nutritionists use the name vitamin D3, instead of 9,10-secocholesta-5,7,10(19)-trien-3-(3-ol (C27H44O). Table 6.1 lists the common names, formulas, and systematic names of some familiar substances. 

Chemists prefer systematic names that precisely identify the chemical composition of chemical compounds. The system for inorganic nomenclature was devised by the International Union of Pure and Applied Chemistry (lUPAC), which was founded in 1921. The lUPAC meets regularly and constantly reviews and updates the system. 

Water (HjO) and ammonia (NHj) are almost always referred to by their common names. 

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An element is paramagnetic if it has any unpaired electrons. Given below are the shorthand notations and number of unpaired electrons present for the elements and ions in their ground states. 

Nomenclature is the term referring to the naming of compounds. In this section, we will investigate how to name inorganic compounds. We will see how to name organic compounds in Chapter 21. In order to name compounds correctly, you will need to memorize certain elements and ions, and you will need to apply a few rules. 

We will use a limited set of elements and ions in our examples. Your instructor, no doubt, will require you to learn additional names. Our limited set begins with the following elements ... 

As discussed in Chapter 9.C, ambient particulate matter contains inorganic elements and ions, including trace metals, as well as graphitic (elemental) carbon and a wide variety of organic compounds and water. Techniques in common use to measure these species are discussed very briefly here. For further details of the principles behind these techniques, the reader should consult instrumental analysis texts (e.g., Skoog et al., 1998). Specific applications of various methods to particles in the atmosphere are described in the book edited by Spurny (1986) as well as the references at the end of this chapter. 

Figure 6.2 Plots of atomization enthalpy, ionization energy and the negative value of the enthalpy of hydration for the Group 1 elements and ions...

In the earliest days of flame AAS, air-propane and air-butane flames were often used to atomize samples, largely because they had a reputation for being simple and safe in operation. However it was soon found that such flames were not satisfactory for breaking up many thermally stable chemical compounds into the free atoms required to obtain atomic absorption. If samples and standards are not atomized to the same extent, erroneous results are obtained. Nowadays the most commonly used flame is the air-acetylene flame. This flame is safe and relatively inexpensive to use, and sufficiently hot at ca. 2200 °C to atomize molecules of many common elements. However it is not sufficiently hot to break the element-oxygen bonds of some elements, the so-called refractory oxide-forming elements. These include, for example, aluminium and silicon. Such determinants require a hotter flame. Also atomization efficiency of some elements may be influenced by matrix elements and ions. For example, phosphate or aluminium depress the atomic absorption signals of calcium in an air-acetylene flame. Thus there is a need for a safe, inexpensive and reliable higher temperature flame in AAS. 

To appreciate the diverse uses of elements and ions in various metabolic processes of the body. 

Give an account of the importance of a balanced diet in providing essential elements and ions for healthy living. 

What evidence is there that root crops that pick up elements and ions from the soil are essential for a balanced diet and healthy living What would happen if we did not take in sufficient quantities of micro quantities of these essential elements Discuss examples of three such ions. 

Don t be confused about what should be included in net ionic equations. It is easier to remember what should be left out Only ions in solution that remain unchanged in solution should be left out to produce net ionic equations all other species must be included. Thus, insoluble compounds (ionic or not), covalent compounds, elements, and ions that change in any way between reactants and products are all included. Remembering what to omit—the spectator ions—is much easier ... 

Thus, scattering factors of various chemical elements and ions can be represented as functions of 9 coefficients Co, i - 04, b - 64 and sin0/X, which are also found in the Intemational Tables for Crystallography, vol. C. 

Mineral ions participate in a wide variety of metabolic processes, electron transport mechanisms, and in nitrate reduction. By manipulation of the level of inorganic elements and ions in the nutrient medium, it is possible to influence the constituents in plants. For over 100 years, tobacco scientists have employed a fundamental research approach in attempts to understand the complex physiology and biochemistry of tobacco involved in the biosynthesis of compounds in tobacco (3973). Their efforts have greatly improved the economics of tobacco production and have led to advancements in understanding of health issues associated with tobacco and its various commercial uses (20A20). 

Metallic and Nonmetallic Elements and Ions in Tobacco, Tobacco Smoke, and Tobacco Substitute Smoke... 

We prefer to retain the more complete dehnitions given here (17.21 17.22), with no assumptions regarding the properties of the elements and ions. The simplification introduced by these assumptions is minimal, and the possibility for confusion is increased. In addition, it is important to realize that thermodynamics is in no way dependent on the assumption that the energies or enthalpies of the elements are zero, which is obviously untrue, and is one of the many factors lending a veil of uncertainty over thermodynamic proceedings. Nor is it dependent on the truth of equation (17.23), which will be discussed in more detail in the next chapter. 

Mores LS (1976) Thermochemical properties of yttrium, lanthanum, and lanthanide elements and ions. Chem Rev 76 827-841... 

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