of the Stability of Dr. A. W. Stewart's Atom. 265 

 Then applying equation (5) we have 



1 1 __ 2 ii+_ r _„ 1 \ 



' 4a 1 [a-r)' 1 + (a 2 + r 2 + ar)i (a-b{l — ej)V 



— /yma) 2 = 0, (10) 

 but 2g + r _1 1 



(a 2 + r 2 -f ar) I 4« (a - ?*) 2 



is always negative whatever values a and r may have (a<r). 



Hence the quantity inside the bracket is still more 

 negative, and the equation cannot be fulfilled. 



Hence the configuration is impossible for equilibrium and 

 the atom would have no features of permanence. 



III. Beryllium — group 2 — no. of electrons = four, no. of 

 valency electrons = two. 



Consider equilibrium of electron C in configuration shown 

 in fig. 4. 



Fig:. 4. 



2 VX.C 'E 



J 



-9Q 



Beryllium atom. 

 Apply equation (5) : we have 



2(_ J_ 1 , _1 



-o + 



2a 



1 



but 



1 ,+ 



)2 (a* + f*)i ( a -/>(l- e )) 2 



+ 7 m rr*} _ mao> 2 = 0, . (11) 



(a— 6(l + e))V v 



9/. 1 1 



(«+/•)- (a 2 + r*)l 4a 2 (a— r) 2 

 P/w7. Ma<?. S. 6. Vol. 38. No. 224. Awa. 1910. T 



