32 CONTEMPORARY SCIENCE 



of electrons required to form the molecule it follows that 

 e = Sn 2p or 



p = 



This simple equation tells us in each case how many 

 pairs of electrons or chemical Bonds must exist in any 

 given molecule between the octets formed. Hydrogen 

 nuclei, however, may attach themselves to pairs of elec- 

 trons in the octets which are not already shared. For 

 example, in the formation of hydrogen fluoride from a 

 hydrogen atom and a flourine atom there are 8 electrons 

 in the shells (e = B) . We place n I in the above equa- 

 tion and find p = o. In other words, the fluorine atoms 

 do not share electrons with each other. The hydrogen 

 nucleus having given up its electron to the flourine atom 

 attaches itself to one of the pairs of electrons of the 

 fluorine octet, and thus forms a molecule having a rela- 

 tively weak external field of force. As a result, hydrogen 

 fluoride is a liquid of low boiling point instead of being 

 salt-like in character. 



The equation given above is applicable to all types of 

 compounds. For example, if we apply it to substances 

 such as sodium fluoride, sulfur fluoride, or potassium 

 fluosilicate, which were previously considered, we find in 

 each case p = o. In other words, there are no pairs of 

 electrons holding the atoms of these compounds together. 

 On the other hand if we consider the compound N 2 H 4 , 

 we find p = i. Since there are only two octets the pair 

 of electrons must be between the two nitrogen atoms 

 while the hydrogen nuclei attach themselves to pairs of 

 electrons of the nitrogen octets. It can be readily shown 

 that this simple theory is in fact identical with the ac- 

 cepted valence theory of organic chemistry and leads to 

 the same structural formulas as the ordinary theory in 

 all those cases where we can take the valance of nitrogen 

 to be 3, oxygen and sulfur 2, chlorine and hydrogen one. 

 In other cases such as those where quinquivalent nitrogen 

 has been assumed, the new theory gives results different 



