178 ISOTOPIC TRACERS AND NUCLEAR RADIATIONS [Chap. 7 



234 238 



UX, —Ul 



4.55X10 y 



24.1 d 



234 



99.65 UX 2 ••' m 



234 

 0.35 UZ «' 7 h 



RaB 



RaA 



Rn 



3.05 m 3.825 d 



I 600 y 



Ro 



lo 



Ull 



62 250 y 2.3X10 y 



210 « 214 



RaC " °-°"% Rac 



19.72 m 

 I 32 m \ \ 19.72 m, 99.96 % 



Pa 



210 



214 



RaD 



22.2 y 



RaC' 



Em 



Ra 



Th 



20.8 d 



206 (5XI0- 7 ) 2I ° 



Tl — ' RoE 



. 4.85 d 



PROTACTINIUM SERIES 



4.85 <) 



STABLE RoG 



RaF 



81 82 83 84 85 86 87 88 89 90 91 92 



ATOMIC NUMBER 



Fig. 50. Uranium-radium series and protactinium series. 



231 233 



UY — AcU 



24.64 h 



AcK 



223 



I % 



•Ac 



Pa 



13.4 y 



3.2X10 y 

 .13.4 y, 99 % 



AcB 



AcA 



An 



ii 2 d 



223 ^ 227 



AcX RdAc 



207 \ J,, 



AcC' r -^^AcC 



2.16 m 



l 2.16 m,0.3 % 



211 



stable AcD 7— AcC' 



\ 



81 82 83 84 85 86 87 88 89 90 91 92 

 ATOMIC NUMBER 



Fig. 51. Actinium-uranium series. 



