This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition. Excerpt: ... 9-0 volts. This value is in extremely good agreement with that calculated from the critical wave length requisite for ionisation by absorption of ultra-violet light quanta. It is evident that the requisite energy equal to Ye can be supplied by the kinetic energy lost by an impinging electron, i.e. l/2mi?, or ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 edition. Excerpt: ... 9-0 volts. This value is in extremely good agreement with that calculated from the critical wave length requisite for ionisation by absorption of ultra-violet light quanta. It is evident that the requisite energy equal to Ye can be supplied by the kinetic energy lost by an impinging electron, i.e. l/2mi?, or by the absorption of a light quantum hv thus--Ve = l/2m. vs = hv. Taking = 135 /m/i we obtain the value 9'20 volte for the value of V determined in this manner. A value of 8 6 volts being obtained by Compton (" Phys. Eev.," 8, 412, 1916), by calculation of the work necessary to remove a valency electron from an atom possessing Bohr's hypothetical structure. Quantitative agreement between the yield of ozone calculated and that actually obtained has, as has already been mentioned, been shown to hold for the case of ozonisatdon by a particle discharge by Lind. Cases of ionisation and ozonisation by electron emission have given more variable results. This is in part due to the great velocity and relatively small size of the electrons which can pass through a vessel containing gas and come to rest on the walls without having made a great number of collisions, thus the major part of its kinetic energy is still retained when it emerges from the gas and strikes the walls. Again, it appears that every collision which an electron makes with a molecule of oxygen, with sufficient energy to dissociate the molecule, is not always effective in doing so. According to P. Kirkby (" Proc. Roy. Soc," 8s, 151, 1911), only 50 per cent. of such collisions are effective. The yield of ozone by electron collision in oxygen, therefore, usually falls far short of the theoretical quantity. CHAPTER Vn. PRODUCTION BY MEANS OP THE SILENT ELECTRIC...
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