412 



Dr. G. von Hevesy on the 



importance. It may be said that the properties of radium G 

 given in this paper do not refer to the product called radium 

 (j by FajanSj but to its mother substance, namely the product 

 which has a period of 19*5 minutes, and is called radium Q v 

 There is thus between radium Ci of known valency, and 

 radium D of known valency, a product radium C ; of unknown 

 valency. 



Table VI. 



Eadioelement. 



i 



Period. 



Valency. 



Eatio of the difference in 

 valency between parent 

 and resultant product/ 

 and the number of po- 

 sitive charges emitted 

 by the parent atom. 





5x10° years 

 24"5 days 

 2 X 10 6 years 



10 4 years(?) 

 1760 years 



3'85 days 



315 mins. 

 26'7 mins. 

 19'5 mins. 

 ? 



16'5 years 



5 days 



136 days 



6 





4 

 6 



4 



2 







probably 2 

 1 

 2 



? 



2 



2 



2 



j =1 

 l-i 



?=1 

 2 



? 



9 



h 

 \ 



is 









Eadium emanation ... 



















1 



Thorium 



Mesothorium 1 



Mesothorium 2 

 Eadiothorium 



Thorium X 



Thorium emanation.. 



Thorium A 



Thorium 33 



Thorium C 



Eadioactinium 

 Actinium X 



Actinium emanation. 



Actinium A 



Actinium B 



Actinium C 



3 X 10io years 

 5' 5 years 



6'2 hours 

 737 days 



3-67 days 



54 seconds 



1/7 second 

 10'6 hours 

 1 hour 







probably 2 

 1 



196 days 

 10'5 days 



3'9 seconds 



1/450 second probably 2 

 36 mins. 1 



2'2 mins. 2 



9 

 P 



I=i 



9 







= 1 



5=1 



9 



9 



