12 The Philippine Journal of Science 1921 
+ . « 
but only because the unsatisfied bonds of — H — are immediately 
satisfied by the formation of a solvated ion, such as H — 9 er” 
H* 
This hydrated hydrogen ion may also be written: 
oa 
H—O-H 
| (2) 
H 
in -O=H} 
| (3) 
H 
or 
H>O<H|* 
t (4) 
H 
The advantage of formula (2) is that it shows the symmetry 
of the compound. It is readily seen that a borrowing bond 
may be considered as a normal bond preceded by the transfer 
a 
of an electron. Imagine —O + —H— to become by transfer 
+ : 
—O-— + —H, which then combine by normal union. Ac- 
| 
tually the transfer does not take place first, but at the moment of 
union there is a distribution of the positive charge. This fact 
is best expressed by formula (4), but (2) is a simpler 
expression of valence relations, 
EXAMPLES 
Na ------ H, H—O—H, H—C. 
THE HELIUM GROUP 
He’, Ne’, A*, Kr, Xe, Nt°. 
Electrons in shell — 0. 
These atoms have zero valence, but according to the octet 
theory they may possibly have the power of combining with 
+ 
oxygen or with — H — as follows: 
+ + 
Xe + —Q-— giving Xec O, Xe + —H— giving Xen H, 
If so, the combination would be very unstable, as these 
“inert” atoms have very weak external fields. 
