Hackh — Modification of the Periodic Table. 487 



From these two generalizations of facts we are entitled 

 to divide the elements into periods, similar to the divi- 

 sions already proposed by Batschinsky, 23 Werner, 24 

 Adams, 24a Harkins, 25 and myself. 20 We have, accord- 

 ingly, the following periods : 



1 from He to F 8 = 2 X 2 2 elements (first short period) 



2 " Ne "CI 8= " " (second " " ) 



3 " A "Brl8 = 2X3 2 " (first long period) 



4 " Kr "I 18= " " (second " " ) 



5 " Xe"8532 = 2X4 2 " (very long period) 



6 " Nt " U 7 elements 



(together with H = 1 X2 2 elements) 



The explanation for this periodic increase in the number 

 of the elements between the rare gases must be found in 

 the constitution of the atoms. That is to say that the 

 positive and negative charges, or corpuscles, in the rare 

 gases form a stable and neutral system. Let us indicate 

 this stable system of negative electrons around the pos- 

 itive nucleus as x, then this x must be 8 or a multiple of 8, 

 for we have in the first period (according to Parson's 

 scheme) 



He Li Be B C N F Ne 



x x+1 x+2 x+3 x+4: £+5 x+6 x-\-l x+8 = 2x 



and so on for the other periods, e. g. the third period : 



A K Ca Sc Ti 

 3x Sx+1 3x+2 3z+3 3^+4 



Ge As Se Br Kr 



4.r+4 4£+5 4;r+6 4.r^-7 4,r+S = ox 



This would indicate that the atoms of the elements near 

 the rare gases constitute more stable systems of elec- 

 trons, and thus exhibit a more distinct characteristic in 

 their properties. On the other hand the larger the num- 

 ber of electrons becomes, the less rigid, and easier inter- 

 changeable- they become. The interchange of electrons 

 may be illustrated by the remaining elements of the fifth 

 period as follows : 



Ce 



Pr 



Nd 



61 



Sm 



En 



Gd 



Tb 



Dv 



Ho 



Ix + 4 



5 



6 



7 



8 



9 



10 



11 



12 



13 



Sx + 











1 



2 



3 



4 



5 



9x + 





















