650 TABLE 711.— GREATEST BINDING ENERGY OF AN ELECTRON— 

 SINGLY-IONIZED ATOMS * f 



* See column 6, Table 623. 



t For reference, see footnote 222, p. 649. 



TABLE 712.— CONSTANTS OF DIATOMIC MOLECULES* 



The attractive force between atoms varies with the distance between centers. When 

 this distance = r e , the sum of the two radii, the force changes from an attraction to a 

 repulsion. The force, D, at this distance, r e , is thus the force necessary to pull the two 

 atoms apart. The energy of separation is generally given. 



D D 



kgcal electron r« 



Substance mole volts A 



H 2 103 4.454 .75 



CH 81 3.5 1.12 



NH 97 4.2 1.08 



OH 102 4.4 .96 



HC1 102 4.40 1.27 



NO 123 5.3 1.15 



2 117 5.09 1.20 



N 2 170 7.35 1.09 



For reference, see footnote 203, p. 624. 



SMITHSONIAN PHYSICAL TABLES 



