68 REACTIONS INDUCED BY IONIZING RADIATION 



8. Hirschfelder, J., and H. S. Taylor, /. Chem. Phys., 6: 783, 1938. 



9. Noyes, W. A., and P. A. Leighton, The Photochemistry of Gases, pp. 153-155, 

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10. Semenoff, N., Chemical Kinetics and Chain Reactions, p. 5, Oxford, 1939. 



11. Herzberg, G., Atomic Spectra and Atomic Structure, Prentice-Hall, 1937. 



12. Franck, J., and E. Rabinowitch, Trans. Faraday Soc, 30: 120, 1934. 



13. Jelly, E. E., Nature, 138: 1009, 1936. Scheibe, G., Z. angew. Chem., 50: 51, 1937. 

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14. Franck, J., and R. Livingston, Revs. Modern Phys., 21: 505, 1949. 



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16. Herzberg, G., Molecular Spectra and Molecular Structure, pp. 425-426, Prentice- 

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19. Magee, J., and M. Burton, J. Am. Chem. Soc, 72: 1965, 1950. 



20. Reference 11, pp. 167, 173. 



21. Hustrulid, A., P. Kusch, and J. T. Tate, Phijs. Rev., 54: 1037, 1938. 



22. Glockler, G., and S. C. Lind, The Electrochemistry of Gases and Other Dielectrics, 

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24. Lind, S. C., and M. Vanpee, J. Phys. Colloid Chem., 53: 898, 1949. 



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28. Zimmerman, G., Ph. D. thesis, University of Chicago, 1949. Platzman, R., 

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DISCUSSION 

 Burton : 



In amplification of points raised by Livingston we may note that in photo- 

 chemical reactions energy absorbed electronically at a particular locus may be 

 internally converted to vibrational energy at another favored locus. In such 

 event rupture of one particular bond, or a particular rearrangement decom- 

 position, may be specially favored. In thermal reactions the energy is initially 

 distributed in many degrees of freedom, and, in general, the most probable 

 primary reaction is that most favored by the frequency factor and particularly 

 by the activation energy. In contrast, in photochemical reactions the process 

 of lowest activation energy is not necessarily the most likely to occur. In radi- 

 ation chemistry there is evidence for a great variety of possible products, related 

 undoubtedly to the fact that primary ionization and primary excitation (both 

 of which are produced by the ionizing radiation) are not restricted to one part 

 of the molecule. Resultant chemical events are shaped by the nature of the 

 initial physical events peculiar to radiation chemistry. The situation is not 

 comparable to the photochemical case. In radiation chemistry one must reckon 



