Element. 



First Group : 

 Ur 

 I 

 UrX 



Ionium 



Ra 



Emanation 



RaA 



-t 

 RaB 



4- 

 RaC 



4- 

 RaD 



4- 

 RaE 



RaF 



Inactive Product 



Atomic 

 Weight. 



238-5 



(234-5) 

 (230-5) 

 226-5 

 (222-5) 

 (218-5) 



(214-5) 



(214-5) 



(210-5) 



(210-5) 



(210-5) 



(206-5) 

 Cp. lead = 207 



Half-Life 

 Period. 



22 days 



1300 years \ 

 or 164 ,, j 

 3-8 days 



3 minutes 



21 ,, 



28 „ 



40 years 



6 days 



143 ,. 



Nature of Exaggerated 

 Emitted Graphic 



Rays. Representation 





rayless 

 rayless 



a 



rayless 



Third Group : 



Act 



4- 



Radioactinium 



4r 



ActX 



Emanation 



Act A 



4' 

 ActB 



ActC 



4- 



Inactive Product 



19-5 days 



10-2 „ 



3-9 seconds 

 36 minutes 

 2-15 ., 



rayless 



o 

 a(/3?) 



a 



rayless 



a/3y 



rayless 



