The Valence of the Argon Group, Etc. 



343 



There is a general similarity, but not an identity. 



The principal facts and conclusions of the paper are: 

 The molecular cohesion, confirming other properties, shows 

 that the argon group of elements have valence. A com- 

 putation of the average number of valences per molecule 

 from the molecular cohesion gave the following results: 

 He, o.i; Ne, 0.32; Ar, 1.12; Kr, 1.23; Xe, 1.80. The valences 

 are apparently fractional, and not whole numbers. The 

 conclusion is that these elements are all zero valent, as far 

 as their chief valences go, but each is divalent in its residual 

 valences. At any one instant of time only a certain pro- 

 portion of the atoms, varying in the different gases, have their 

 residual valences open, consequently the average number of 

 valences actually open, or active, per molecule is less than two. 

 One residual valence is positive, the other negative; and 

 hence the combining power of the atoms is very weak, since 

 on dissociation an electrically neutral atom is formed, by the 

 saturation within the atom of the oppositely charged valences. 

 This explanation enables us to understand, also, why there 

 is a progressive increase in solubility of these gases in water 

 from helium to xenon if solution be a process involving the 

 union of solvent and solute through their residual valences. 



University of Chicago 



