400 PHENOMENA, ATOMS, AND MOLECULES 



Another set of compounds that must have a special structure are various 

 compounds of boron such as B2H6. 



Most compounds containing molecules of H2O, NH3, etc., are readily 

 accounted for by Postulate 3 but many of these should be considered by 

 methods somewhat different from those developed here. 



In double molecules such as H4O2 (in ice), H2F2, and in compounds 

 such as KHF2, etc., it seems that the hydrogen nuclei instead of forming 

 duplets with electrons in the same atom, form duplets in which the two 

 electrons are in different atoms. The hydrogen nucleus itself thus acts as a 

 bond in such a case. Latimer and Rodebush have made a somewhat similar 

 suggestion in regard to hydrogen nuclei acting as bonds. They consider, 

 however, that the hydrogen nucleus acts on two pairs of electrons : one pair 

 in each of the two atoms. It seems to the writer much more probable that 

 the hydrogen nucleus is no more able to attract four electrons than is the 

 nucleus of other atoms. Since the first layer of electrons in all atoms con- 

 tains only 2 electrons it seems probable that the hydrogen in this case also 

 holds only two electrons and that these form the definite stable group which 

 we have termed the duplet. 



The writer plans to consider the quantitative aspects of these valence 

 theories in subsequent papers. It is aimed to put Postulates i and 3 into a 

 form that will permit at least rough calculations of the relative stabilities 

 of various substances as measured, for example, by their heats of formation. 



