Table of the Isotopes
11-134 Elem. or Isot. 158 159
160 161
Gd Gd
Gd Gd
Natural Abundance (Atom %) 24.84(7)
21.86(19)
Atomic Mass or Weight
Half-life/ Resonance Width (MeV)
Decay Mode/ Energy (/MeV)
157.924104 158.926389
18.6 h
β- 0.971
159.927054 160.929669
> 1.9 × 1019 y 3.66 m
β- ββ- /1.956
162
Gd
161.930985
8.4 m
β- /1.39
163
Gd
162.9340
1.13 m
β- /3.1
Gd Gd 166 Gd 167 Gd 168 Gd 169 Gd
163.9359 164.9394 165.942 166.946 167.948 168.953
45. s 10 s ~ 4.8 s
β- /2.3 β-
164 165
65
Tb
158.92535(2)
Tb Tb 139 Tb
137.9532 138.9483
135 138
0.9 ms
p
2.4 s
β+, EC/11
Tb Tb 142m Tb 142 Tb 143 Tb 144m Tb 144 Tb 145m Tb
140.9415
3.5 s 25 μs 0.30 s 0.60 s 12. s 4.1 s < 1.5 s 30. s
β+, EC/~ 8.3
Tb Tb
144.9293
Tb Tb
145.92725
Tb
146.92405
142m2
145
146m
146
147m
147
Tb
148m
487_S11.indb 134
141.9387 142.9351 143.93305
0+ 3/2-
1.56/85
0+ 5/2-
1.0/
0+
Nuclear Elect. Magnetic Quadr. Mom. (nm) Mom. (b) -0.44
γ-Energy / Intensity (MeV/%) Tb k x-ray 0.36351 0.058-0.855 Tb k x-ray 0.1023 0.3149 0.3609 0.4030 0.4421 0.2868 0.214 1.685
0+ 0+
(0.040-1.015)
p/1.179
1.6 s
139.946
141
0.971/58 0.913/29 0.607/12
Spin (h/2 π)
0+
Tb
140
Particle Energy/ Intensity (MeV/%)
0.109 0.120 0.329 0.355–0.740
β+, EC/ β+, EC/10. β+, EC/7.4 IT β+, EC/8.4 β+, EC/~ 6.6
40+ 11/251+ 11/2-
β+, EC/6.5 β+ /76 / EC/24 /
½+ (5-)
~ 8. s 1.8 m
β+ /8.1 β+ /35 / EC/65 /
1+ 11/2-
1.6 h
β+ /42 /4.61 EC/58 /
5/2+
2.3 m
β+ /25 / EC/75 /
9+
23. s
ann.rad./ 0.2577 0.5370 0.9876 ann.rad./ Gd k x-ray 1.0789 1.5795
+1.70
ann.rad./ Gd k x-ray 1.3977 1.7978 ann.rad./ Gd k x-ray 0.6944 1.1522 (0.120–3.318) ann.rad./ Gd k x-ray 0.3945 0.6319 0.7845
4/17/06 11:00:06 AM