THE STRUCTURE OF ATOMS 31 



5 for chlorine, etc. But more especially it does not ex- 

 plain the structure of organic compounds and such sub- 

 stances as H 2 , C1 2 , O 2f N 2 H 4 , PC1 3 , etc. 



J. J. Thomson, Stark, Bohr, and others had suggested 

 that pairs of electrons held in common by two adjacent 

 atoms may function in some cases as chemical bonds be 

 tween the atoms, but this idea had not been combined with 

 the conception of the stable groups of electrons or octets. 

 G. N. Lewis, in an important paper in 1916, advanced the 

 idea that the stable configurations of electrons in atom 

 could share pairs of electrons with each other and he 

 identified these pairs of electrons with the chemical bond 

 of organic chemistry. This work of Lewis has been the 

 basis and the inspiration of my work on valence and 

 atomic structure. 



As a result of the sharing of electrons between octets, 

 the number of octets that can be formed from a given 

 number of electrons is increased. For example, two 

 fluorine atoms, each having seven electrons in its outside 

 shell, would not be able to form octets at all except by 

 sharing electrons. By sharing a single pair of electrons, 

 however, two octets can be formed since two octets hold- 

 ing a pair in common require only 14 electrons. This is 

 clear if we consider two cubes with electrons at each of 

 the eight corners. When the cubes are placed so that an 

 edge of one is in contact with an edge of the other a sin- 

 gle pair of electrons at the ends of the common edge will 

 take the place of four electrons in the original cubes. 

 For each pair of electrons held in common between two 

 octets there is a decrease of two in the total number of 

 electrons needed to form the octets. 



Let e represent the number of electrons in the outside 

 shell of the atoms that combine to form a molecule. Let 

 n be the number of octets that are formed from these e 

 electrons, and let p be the number of pairs of electrons 

 which the octets share with one another. Since every 

 pair of electrons thus shared reduces by two the number 



