Philosophical Magazine

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Taylor & Francis, 1920 - Physics
 

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Page 89 - Above a certain voltage, the intensity of any line per unit number of electrons reaching the anode attains a saturation value, in agreement with the quantum hypothesis which requires that the number of quanta radiated be proportional to the number of collisions, and hence (approximately) to the number of electrons present. Curves are given showing the relative intensities of the prominent caesium lines at various voltages. The ratio of intensities of the components of the first doublet of the principal...
Page 88 - The doublet 1.5 s — 2p, is alone produced under excitation of 1.5 to 3.9 volts accelerating field. The intensity of both of these lines gradually increases approximately proportional to the total number of electrons reaching the anode until the ionization potential is reached. At this point a pronounced decrease in intensity of these two lines occurs, amounting to the factor onethird. This decrease takes place at the voltage at which the...
Page 195 - The effect of a second group of the same or of a different kind is to decrease the effect of the first. Compare, for instance, toluene with xylene; catechol quinol and cresol with phenol ; and methyl cyclohexanol with cyclohexanol. The simpler the group the more effective it is. Compare cymene with toluene or xylene, and benzyl alcohol with phenol.
Page 88 - ... spectrum or above 2.7 volts in a group spectrum, rapidly approaches infinity as the accelerating potential in the arc is decreased. This ratio is 350 in a...
Page 87 - ... 1 . A simple explanation is offered of fluorescence phenomena in vapors of the alkali metals. A mechanism of absorption of radiation is described and the theory proposed by K. Compton, that the ionization of an atom below the ionization potential may be explained by absorption of radiation arising in other atoms from electronic-atomic impact of insufficient energy to ionize, is further discussed. This hypothesis suggests that vapors of the alkali metals may be so stimulated that the...
Page 85 - Logarithm of intensity of various caesium lines as a function of the applied exciting voltage volts and 3.0 volts. Neither can they be accounted for by velocity distribution due to temperature of the cathode. Thus the fractional number F of emitted electrons having a velocity greater by V0...
Page 87 - THEORETICAL On the basis of several possible theories of atomic structure it is shown that the normal operation of an arc below ionization might result in the excitation of a single-line spectrum, a singleseries spectrum, or a group spectrum consisting of certain lines of different series. This latter conclusion follows from an extension of Bohr's theory. Thus, if inelastic electronic-atomic impact occurred resulting in the ejection of an electron to the...
Page 244 - GUINEA. according to the number cf books required at one time. Subscriptions may begin at any date. Books may be retained as long or exchanged as frequently as desired. The Library NEW READING AND WRITING ROOM is open daily.
Page 378 - There is now reigning in philosophy and in science an apathetic acquiescence in the conclusion that no coherent account can be given of nature as it is disclosed to us in sense-awareness, without dragging in its relations to mind. The modern account of nature is not, as it should be, merely an account of what the mind knows of nature ; but it is also confused with an account of what nature does to the mind. The result has been disastrous both to science and to philosophy, but chiefly to philosophy.
Page 417 - Electrons Held in Common.— Two octets may hold 1, 2, or sometimes even 3 pairs of electrons in common. A stable pair and an octet may hold a pair of electrons in common. An octet may share an even number of its electrons with 1, 2, 3, or 4 other octets. No electrons can form parts of more than two octets.

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