Scientific notation defined

The use of scientific notation to describe ion concentrations is somewhat cumbersome, and chemists have agreed to employ a pH scale to state the concentration of hydrogen ions (the capital H in pH stands for hydrogen). They define pH to be the negative logarithm to base 10 of the hydrogen ion concentration ... 

Recall from Table 4-1 that the masses of both protons and neutrons are approximately 1.67 x 10 g. While this is a very small mass, the mass of an electron is even smaller—only about that of a proton or neutron. Because these extremely small masses expressed in scientific notation are difficult to work with, chemists have developed a method of measuring the mass of an atom relative to the mass of a specifically chosen atomic standard. That standard is the carbon-12 atom. Scientists assigned the carbon-12 atom a mass of exactly 12 atomic mass units. Thus, one atomic mass unit (amu) is defined as the mass of a carbon-12 atom. Although a mass of 1 amu is very nearly equal to the mass of a single proton or a single neutron, it is important to realize that the values are slightly different. As a result, the mass of silicon-30, for example, is 29.974 amu, and not 30 amu. Table 4-2 gives the masses of the subatomic particles in terms of amu. 

It should be clear that these reactions of weak acids and bases are a special case of the equilibrium that we have been exploring throughout this chapter. When any acid dissolves in water, hydronium ions are always formed as one of the products. This species is so common that an additional way to describe its concentration has been devised. To avoid dealing with small numbers in scientific notation, we often use the pH scale, in which pH is defined as the negative logarithm of the hydronium ion concentration ... 

A list of commonly encountered ligand abbreviations is given in Table 10. While it is generally accepted to use abbreviations for ligands in a pseudo formula ([Co(edta)(H20)] ) within textual material to stand for a cumbersome name, it should be recognized that ambiguities in interpretation can always occur with this type of notation. Thus, all abbreviations should be defined within a suitable span of text. Scientific publications should certainly contain at least one formula per compound which is composed only of the internationally accepted atomic symbols, and which accurately defines the composition of the compound or compounds of primary interest reported in the publication. 

I will reconstruct and interpret Vernadsky s views on the space-time problem and define the place of this problem in his theoretical system (i.e. the connection between his treatment of the ace-time problem and other fundamental ideas). I use the term reconstruction here, because, first, I was forced elaborating this theme, to deal, partially, with disparate notations in Vernadsky s published works and, second, Vernadsky investigated this subject mostly late in his life and so, unfortunately, did not have time to express his thoughts clearly and completely. Besides, one should bear in mind, that the scientific views of Vernadsky on the nature of space and time changed considerably towards the end of 1930 s and the beginning of the 1940 s. Therefore, the reconstruction we attempt here is not only a hermeneutical but a logical reconstruction of Vernadsky s views as well. 

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