Atomic weight table

A relative scale of atomic weights (as the weighted average of all forms, or isotopes, of a particular element found in nature) has been developed. The base of this scale is the assignment of a mass of 12.0000 to the isotope of carbon containing 5 protons, 5 neutrons, and 6 electrons. An atomic weight table can be found in Table 2.2. 

Elements 43, Masurium 61, Illinium 84, Polonium or Radium F 89, Actinium 91, Uranium Xs do not appear in the atomic weight tables. Although their existence has been indicated by means of X-rays or radioactive properties, they have not been isolated in amounts to allow of atomic weight determination. 

Since the difference in bond energies between Si—X and C—X decreases with increasing halogen atomic weight (Table III), somewhere along the line one should expect to observe both insertion and addition products from the same reaction, which would reflect the competitive preference of insertion vs. addition after the initial attack of the oligomeric difluorosilylene. 

The value given in the International Atomic Weight Tables for gold at present is 197.2 it is not unlikely that this will soon be revised to the mass-spectrographic value by the International Committee. 

Two chlorides of a metal were found on analysis to contain 50.91% and 46.37%, respectively, of the metal. What are the possible values of the atomic weight of the metal What is the metal (Refer to die atomic weight table.)... 

General Chemistry 1.1.9 Atomic Weights Table 1.9. Atomic Weights... 

Appendix to reports, 455-458 Approach to design, 11-12 Area, mean, for heat transfer, 587-588 ASPEN PLUS, 127 Asset guide-line period, 273-275 Assets in accounting, 139-145 definition of, 139 types of, 140-142 Assumed liability, 262 Assumptions in design, 11 Atomic weights, table of, 891... 

Average molecular Calculated from the elemental composition using mass (molecular average atomic weights (Table 2.2). It is the chemical weight) mass. In MS, it can be important in the analysis of large molecules. ... 

As was discovered well after the turn of the twentieth century, when the structure of the atom was discerned, the order of the elements is determined unambiguously by the property of atomic number, which corresponds to the number of protons in the nucleus of the atoms of any particular element. It emerges that in certain parts of the modem periodic table the triad relationship tmns out to be exact if atomic numbers are used instead of atomic weights (table 2.11). For example, a number of the triads discovered by Dobereiner behave in this manner. 

L. K. Nash suggested that it was in thinking over the solubility results that Dalton arrived at the chemical atomic theory. Nash discussed in detail the alternative explanations of Roscoe and Harden and of Meldrum, and concluded that the atomic weight table is introduced logically into the solubility paper in order to provide some explanation of the fact, difficult to understand on the mechanical hypothesis, that different gases have different solubilities. The experiments on solubility were begun early in 1803, perhaps in January, but the first mention of atomic weights was on 6 September 1803. 

Thomson, therefore, some time before Berzelius (see Vol. IV), had extended Dalton s atomic theory to the metals and to acids and bases. W. C. Henry says his father William Henry and he were told by Dalton that the atomic theory was deduced to explain Richter s table of equivalents published in BerthoUet s Statique Chimique in 1803 (see p. 678). Dalton s early atomic weight tables, however, never mention the combining weights of acids and alkalis, the compounds investigated by Richter, whose name first occurs in Dalton s diary on 19 April 1807. Thomson, in his account of Dalton s theory in 1807, says it explains Richter s law of equivalents and it was probably Thomson who drew Dalton s attention to Richter, since Dalton was in Edinburgh when he first mentions Richter in his diary. Higgins also had developed his views in relation to gaseous compounds, as Dalton did (see p. 739). 

An anticipation of this has actually been realised.. . . The discovery of gallium, with atomic weight 68, has verified this prediction by Mendeleev. By contrast, the eleventh edition, published four years earlier, neither listed gallium in the atomic weights table nor mentioned Mendeleev. This implies that gallium s discovery was crucial to this early recognition of the periodic law. 

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