T (average Rays (given out in Element Atomic time-period--half each Weight transformed) decomposition) --------------------------------------------------------------------- Uranium I 238 4.5 × 10^9 yrs. Alpha Uranium X1 234 23.8 days Beta, Gamma Uranium X2 234 1.15 min. Beta, Gamma Uranium II 234 About 2 × 10^6 yrs. Alpha Ionium 230 About 9 × 10^4 yrs. Alpha Radium 226 (+) 1700 yrs. Alpha Niton (Emanation) 222 3.85 days Alpha Radium A 218 3.05 min. (?) Alpha Radium B 214 26.8 min. (?) Beta, Gamma Radium C 214 19.5 min. (?) Alpha, Beta, Gamma Radium C′ 214 10^{-6} sec. (?) Alpha Radium D 210 (+) 16 yrs. Beta, Gamma Radium E 210 (+) 4.85 days Beta, Gamma Radium F (Polonium) 210 (+) 136.5 days Alpha Radium G (End-product 206 ............... ............... uranium-lead) --------------------------------------------------------------------- URANIUM Y (ACTINIUM) SERIES T (average Rays (given out in Element Atomic time-period--half each Weight transformed) decomposition) --------------------------------------------------------------------- Uranium Y (branching 234 (+) 24.6 hrs. Beta from Uranium II) (2.2 days?) Protoactinium 230 About 10^4 yrs. (?) Alpha Actinium 226 20 yrs. Beta Radio-actinium 226 19 days Alpha Actinium X 222 (+) 11.2 days Alpha Actinium (Emanation) 218 3.92 sec. Alpha Actinium A 214 .002 sec. Alpha Actinium B 210 36 min. (?) Beta, Gamma Actinium C 210 2.16 min. (?) Alpha Actinium D 206 4.76 min. Beta, Gamma Actinium E (End-product 206 ............... ............... actinium-lead) --------------------------------------------------------------------- THORIUM SERIES