. Carnegie Institution of Washington publication. 100% 56 INFRA-RED TRANSMISSION SPECTRA. in the sulphates examined, especially for K, Ba, Ca, and Pb, which have a common band at /*,. The sulphates of the metals K, Rb, and Cs have been compared by Tutton,1 who has shown that both as regards crystalline form, specific gravity, thermal expansion, and corresponding refractive indices the Rb salt lies between the K and Cs salts. These mono- valent elements occupy con- secutive positions in the even series of Mendeleef's table. The next even series is Ca, Sr, and Ba, the trans- mission curves o
. Carnegie Institution of Washington publication. 100% 56 INFRA-RED TRANSMISSION SPECTRA. in the sulphates examined, especially for K, Ba, Ca, and Pb, which have a common band at /*,. The sulphates of the metals K, Rb, and Cs have been compared by Tutton,1 who has shown that both as regards crystalline form, specific gravity, thermal expansion, and corresponding refractive indices the Rb salt lies between the K and Cs salts. These mono- valent elements occupy con- secutive positions in the even series of Mendeleef's table. The next even series is Ca, Sr, and Ba, the trans- mission curves of which are before us. The following odd series contains Mg, which just precedes Ca and Cd, which lie between Sr and Ba. In other words, the elements lie in the order Mg, Ca, Sr, Cd, Ba, while the maximum of the ab- sorption band occurs in the order , , , , p. Whether this is a true shift, with increase in molecular weights, needs further examination. The data presented are certainly very suggestive of a real shift, with increase in mole- cular weight of the metal. This same shifting of the maximum, with increase in molecular, will be noticed in the reflection curves of SrSO4 and BaSO4; in the former the maxima are at , , and /j., while in the latter the maxima are shifted to , , and /A. Drude2 has shown that in the ultra-violet the absorption band is due to the sympathetic vibrations of particles which have a charge and mass identical with the "ion" (or "corpuscle"), while, in the infra-red, the absorption bands are due to particles which have a mass of the order of magnitude of the molecule. From this standpoint one would expect. 0123 FIG. 42.—Sulphuric acid («); Cadmium sulphate. 1 See Miers, Mineralogy. 2Drude: Ann. cler Phys. (4), 14, p. 677, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these ill
Size: 1291px × 1935px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1900, bookyear1906
