Sec. 7.12] SEABORG AND PERLMAN TABLE OF ISOTOPES 



237 



Isotope 

 Z A 



66 Dy'ss 



Dyiei 



Dyire 

 Dyi«3 

 Dyi»4 



Dyl«6m 



DyH5 



67 Ho" 



Ho 1 "' 1 ' 2 



Ho 112 ' 1 " 



Ho 183 



Ho 114 



Ho'« 

 Ho 1 " 



68 Eri«2 

 Er'" 

 Eri«6 

 Er>»« 

 Eri" 

 Er'«8 

 Eriss 



E r l«9.171 



Er"0 



Er"» 



Class 



El-"' 



A 



res.n.act. 



A 



m.s. 



D 

 C 



B 

 D 



A 



m.s. 



B 



F 



B 



Per cent 

 abundance 



. 0902 

 2.294 



18.88 



25.53 



24.97 



28.18 



100 



1 

 1.5 



32.9 



24.4 

 26.9 



14.2 



Type of 

 radiation 



I.T., e~ 

 0~, 7 



K(?) 



K(?), y, e- 



0\ K, 7 



K, e~ 

 0- 



0- 



/S", 7. e- 



Half-life 



1.25 min 



145 min; 

 140 min; 

 2.5 hr 



0', 7 



~ 20 min 

 60 days 



4.5 hr 



7 days 



35 min; 

 47 min 



27.0 hr; 



27.5 hr; 

 27.3 hr; 

 30 hr 



1.1 mm 



9.4 days 

 6 min; 



7 min 



7.5 hr; 

 5.7-7.1 hr; 

 12 hr 



Energy of radiation, Mev 



Particles 



20 hr 



0.13(e-) 



abs. Al 

 0.42, 0.88, 



1.25 



spect.; 



1.20 abs. 



coincid.; 



1.18 



spect.; 



1.40cl.ch. 



0.6, 0.16(e") 



abs. Al 



2.O03 + ), 



0.3 (e-) 



spect., 



abs. Al 

 0.4(«-) abs. 



Al 

 0.7 abs. Al 



1.8 abs. Al; 

 1.9 abs.; 

 1.6 abs. 



0.33 spect. 



1.49(6 %), 

 1.05 



(71 %), 

 0.67 

 (22 %) 

 spect., 

 coincid. 



0.6 abs. Al 



7-rays 



0.091, 0.37, 

 0.78 spect. 

 conv., 

 spect.; 

 1.1 abs. 

 coincid.; 

 ~ 1, 0.37 

 spect. 



1.1 abs. Pb 



No 



0.81(22 %) 

 0.31 

 (71 %), 

 0.113 



(71 %) 

 spect., 

 spect. 

 conv. 



Produced 

 by 



Dy-H-7 

 Dy"W-w- 7 

 Dy-n-7 

 Dy 164 -n-7 



Tb-a-3w 

 Tb-a-2n 

 Dy-d-2n 



Dy-p-n 

 Tb-a-n 

 Dy-J-s 



T>y-p-n 



Ho-w-2«(?) 

 Dy-p-n 



Ho-n-y 



Er-n-2n(?) 



Er-n-7 

 Er-n-7 



Er-n-7, 

 parent of 

 Tm' 7 "" 

 (70%), 



Tm'"i 

 (30 %) 



Er-n-7 



