Atomic-weight Sentence Examples
The atomic weight of the element has been determined by analysis.
It is now agreed that the molecule of water contains two atoms of hydrogen and one of oxygen, so that the atomic weight of oxygen becomes 16, and similarly that the molecule of ammonia contains three atoms of hydrogen and one of nitrogen, and that consequently the atomic weight of nitrogen is 14.
One remarkable discovery, however, of general interest, was the outcome of a long series of delicate weighings and minute experimental care in the determination of the relative density of nitrogen gas - undertaken in order to determine the atomic weight of nitrogen - namely, the discovery of argon, the first of a series of new substances, chemically inert, which occur, some only in excessively minute quantities, as constituents of the 1 The barony was created at George IV.'s coronation in 1821 for the wife of Joseph Holden Strutt, M.P. for Maldon (1790-1826) and Okehampton (1826-1830), who had done great service during the French War as colonel of the Essex militia.
The atomic weight was determined by Cleve.
The atomic weight of cadmium was found by 0.Advertisement
Many varying values have been given for the atomic weight of molybdenum.
As the atomic weight of the element increases, it is found that the solubility of the sulphates in water decreases.
The atomic weight was determined by Berzelius, Erdmann and Marchand, Dumas and Stas.
This generalization was of great value inasmuch as it permitted the deduction of the atomic weight of a non-gasifiable element from a study of the densities of its gasifiable compounds.
Dulong to investigate relations (if any) existing between specific heats and the atomic weight.Advertisement
This states that " the atomic heat (the product of the atomic weight and specific heat) of all elements is a constant quantity."
This law-purely empirical in origin-was strengthened by Berzelius, who redetermined many specific heats, and applied the law to determine the true atomic weight from the equivalent weight.
C. Winkler decided the atomic weight of germanium by similar reasoning.
If the crystal structure be regarded as composed of 0 three interpenetrating point systems, one consisting of sulphur atoms, the second of four times as many oxygen atoms, and the third of twice as many potassium atoms, the systems being so arranged that the sulphur system is always centrally situated with respect to the other two, and the potassium system so that it would affect the vertical axis, then it is obvious that the replacement of potassium by an element of greater atomic weight would specially increase the length of w (corresponding to the vertical axis), and cause a smaller increase in the horizontal parameters (x and 1/ '); moreover, the increments would advance with the atomic weight of the replacing metal.
Numerous determinations of the atomic weight of nitrogen have been made by different observers, the values obtained varying somewhat according to the methods used.Advertisement
Guye has given a critical discussion of the relative accuracy of the gravimetric and physico-chemical methods, and favours the latter, giving for the atomic weight a value less than 14.01.
Thus a relation between susceptibility and atomic weight is clearly indicated.
According to the notation adopted by Meyer the atomic susceptibility k=KX atomic-weight/ (density X 1000).
The atomic weight of silicon has been determined usually by analysis of the halide compounds or by conversion of the halides into silica.
Rose determined the atomic weight to be 47.72 (H =1).Advertisement
The atomic weight of gold was first determined with accuracy by Berzelius, who deduced the value 195.7 (H= i) from the amount of mercury necessary to precipitate it from the chloride, and 195.2 from the ratio between gold and potassium chloride in potassium aurichloride, KAuC1 4.
It seems also that the charge would increase with the atomic weight of the element.
A considerable amount of work has been done on determinations of the atomic weight of tellurium, the earlier results giving the value 128.
The atomic weight of caesium has been determined by the analysis of its chloride and bromide.
The atomic weight of fluorine has been determined by the conversion of calcium, sodium and potassium fluorides into the corresponding sulphates.Advertisement
The atomic weight of praseodymium is 140.5.
Stas, from the analysis of pure silver iodate, and by C. Marignac from the determinations of the ratios of silver to iodine, and of silver iodide to iodine; the mean value obtained for the atomic weight being 126.53.
In 1902, in an "attempt at a chemical conception of the ether," he put forward the hypothesis that there are in existence two elements of smaller atomic weight than hydrogen, and that the lighter of these is a chemically inert, exceedingly mobile, all-penetrating and all-pervading gas, which constitutes the aether.
Roughly speaking the difference in frequency is proportional to the square of the atomic weight.
The roots of the three series have frequencies which diminish as the atomic weight increases, but not according to any simple law.
The velocities ranged from about 400 to 1900 metres, the metals of small atomic weight giving as a rule the higher velocities.
As the atomic weight of the haloid increases the spectrum is displaced towards the red.
The atomic weight of magnesium has been determined by many observers.
Deville accordingly returned to pure chemistry and invented a practicable method of preparing sodium which, having a lower atomic weight than potassium, reduced a larger proportion.
The atomic weight of thallium was determined very carefully by Crookes, who found T1=204.2 (0= 16); this figure was confirmed by Lepierre in 1893.
The atomic weight of oxygen is now generally taken as 16, and as such is used as the standard by which the atomic weights of the other elements are determined, owing to the fact that most elements combine with oxygen more readily than with hydrogen (see ELE Ment).
The atomic weight of manganese has been frequently determined.
He concluded that the first contained the chloride of berzelium, having an atomic weight of 212, the second contained thorium chloride, and the third the chloride of carolinium, having an atomic weight of 255.6.
The atomic weight has been variously given.
The atomic weight has been determined by many investigators; the chief methods employed being the analysis and synthesis of the trioxide and the analysis of the hexachloride.
Thus, as the atomic weight increases, the state of aggregation changes from that of a gas in the case of fluorine and chlorine, to that of a liquid (bromine) and finally to that of the solid (iodine); at the same time the melting and boiling points rise with increasing atomic weights.
The halogen of lower atomic weight can displace one of higher atomic weight from its hydrogen compound, or from the salt derived from such hydrogen compound, while, on the other hand, the halogen of higher atomic weight can displace that of lower atomic weight, from the halogen oxy-acids and their salts; thus iodine will liberate chlorine from potassium chlorate and also from perchloric acid.
All four of the halogens unite with hydrogen, but the affinity for hydrogen decreases as the atomic weight increases, hydrogen and fluorine uniting explosively at very low temperatures and in the dark, whilst hydrogen and iodine unite only at high temperatures, and even then the resulting compound is very readily decomposed by heat.
The atomic weight of antimony has been determined by the analysis of the chloride, bromide and iodide.
Numerous determinations of the atomic weight of selenium have been made.
The atomic weight of phosphorus was determined by Berzelius, Pelouze, Jacquelin, Dumas, Schrotter, Brodie and van der Plaats.
The absence of lines of the spectrum of any element from the solar spectrum is no proof that the element is absent from the sun; apart from the possibility that the high temperature and other circumstances may show it transformed into some unknown mode, which is perhaps the explanation of the absence of nitrogen, chlorine and other non-metals; if the element is of high atomic weight we should expect it to be found only in the lowest strata of the sun's atmosphere, where its temperature was nearly equal to that of the central globe, and so any absorption line which it showed would be weak.
The atomic weight of arsenic has been determined by many different chemists.
Another 21% of the air is oxygen, with the molecules having an atomic weight of 32.
He thus arrived at the conception of a definite atomic weight peculiar to the particles of each gas, and he thought that he could determine these atomic weights, in terms of one of them, by means of the quantitative analysis of compounds.
To take the simplest possible case, if Dalton had been correct in assuming that the molecule of water was made up of one atom of oxygen and one of hydrogen, then the experimental fact that water contains eight parts by weight of oxygen to one part of hydrogen, would at once show that the atom of oxygen is eight times as heavy as the atom of hydrogen, or that, taking the atomic weight of hydrogen as the unit, the.
Similarly, Dalton's diagram for ammonia, together with the fact that ammonia contains 4.67 parts of nitrogen to one of hydrogen, at once leads to the conclusion that the atomic weight of nitrogen is 4.67.
The symbol, like that of Dalton, always stands for the atomic weight of the element, that is, while H stands for one part by weight of hydrogen, 0 stands for 16 parts of oxygen, and so on.
The accepted atomic weight is accordingly double the density, i.e.
The atomic weight of the element was determined by C. Winkler by analysis of the pure chloride GeCl4, the value obtained being 72.32, whilst Lecoq de Boisbaudran (Comptes rend us, 1886, 103, 45 2), by a comparison of the lines in the spark spectrum of the element, deduced the value 72.3.
He called this proportion the " atom," since it invariably enters compounds without division, and the weight of this atom is the atomic weight.
According to its position in the periodic classification of the elements one would expect its atomic weight to be less than that of iodine, instead of approximately equal, and on this account many efforts have been made to isolate another element from tellurium compounds, but none have as yet been successful.
In his researches, Roscoe showed that the atomic weight of the metal as determined by Berzelius and the formulae given to the oxides were incorrect, and pointed out that the element falls into its natural place in group V of the periodic classification along with phosphorus and arsenic, and not in the chromium group where it had originally been placed.