Isotopes of lutetium

Naturally occurring lutetium (Lu) is composed of 1 stable isotope 175Lu (97.41% natural abundance) and one long-lived radioisotope, 176Lu with a half-life of 3.78 × 1010 years (2.59% natural abundance). 34 radioisotopes have been characterized, with the most stable, besides 176Lu, being 174Lu with a half-life of 3.31 years, and 173Lu with a half-life of 1.37 years. All of the remaining radioactive isotopes have half-lives that are less than 9 days, and the majority of these have half-lives that are less than a half an hour. This element also has 18 meta states, with the most stable being 177mLu (t½ 160.4 days), 174mLu (t½ 142 days) and 178mLu (t½ 23.1 minutes).

The isotopes of lutetium range in atomic weight from 149.973 (150Lu) to 183.961 (184Lu). The primary decay mode before the most abundant stable isotope, 175Lu, is electron capture (with some alpha and positron emission), and the primary mode after is beta emission. The primary decay products before 175Lu are isotopes of ytterbium and the primary products after are isotopes of hafnium.

Standard atomic mass: 174.967(1) u

Table

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life[n 1] decay
mode(s)[1][n 2]
daughter
isotope(s)[n 3]
nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
150Lu 71 79 149.97323(54)# 43(5) ms p (80%) 149Yb (2+)
β+ (20%) 150Yb
150mLu 34(15) keV 80(60) µs
[30(+95-15) µs]
(1,2)
151Lu 71 80 150.96758(43)# 80.6(19) ms β+ 151Yb (11/2-)
151mLu 77(5) keV 16(1) µs (3/2+)
152Lu 71 81 151.96412(21)# 650(70) ms β+ (85%) 152Yb (5-,6-)
β+, p (15%) 151Tm
153Lu 71 82 152.95877(22) 0.9(2) s β+ 153Yb 11/2-
α 149Tm
153m1Lu 80(5) keV 1# s 1/2+
153m2Lu 2502.5(4) keV >0.1 µs 23/2-
153m3Lu 2632.9(5) keV 15(3) µs 27/2-
154Lu 71 83 153.95752(22)# 1# s β+ 154Yb (2-)
154m1Lu 58(13) keV 1.12(8) s (9+)
154m2Lu >2562 keV 35(3) µs (17+)
155Lu 71 84 154.954316(22) 68.6(16) ms α (76%) 151Tm (11/2-)
β+ (24%) 155Yb
155m1Lu 20(6) keV 138(8) ms α (88%) 151Tm (1/2+)
β+ (12%) 155Yb
155m2Lu 1781.0(20) keV 2.70(3) ms (25/2-)
156Lu 71 85 155.95303(8) 494(12) ms α (95%) 152Tm (2)-
β+ (5%) 156Yb
156mLu 220(80)# keV 198(2) ms α (94%) 152Tm (9)+
β+ (6%) 156Yb
157Lu 71 86 156.950098(20) 6.8(18) s β+ 157Yb (1/2+,3/2+)
α 153Tm
157mLu 21.0(20) keV 4.79(12) s β+ (94%) 157Yb (11/2-)
α (6%) 153Tm
158Lu 71 87 157.949313(16) 10.6(3) s β+ (99.09%) 158Yb 2-
α (.91%) 154Tm
159Lu 71 88 158.94663(4) 12.1(10) s β+ (99.96%) 159Yb 1/2+#
α (.04%) 155Tm
159mLu 100(80)# keV 10# s 11/2-#
160Lu 71 89 159.94603(6) 36.1(3) s β+ 160Yb 2-#
α (10−4%) 156Tm
160mLu 0(100)# keV 40(1) s
161Lu 71 90 160.94357(3) 77(2) s β+ 161Yb 1/2+
161mLu 166(18) keV 7.3(4) ms IT 161Lu (9/2-)
162Lu 71 91 161.94328(8) 1.37(2) min β+ 162Yb (1-)
162m1Lu 120(200)# keV 1.5 min β+ 162Yb 4-#
IT (rare) 162Lu
162m2Lu 300(200)# keV 1.9 min
163Lu 71 92 162.94118(3) 3.97(13) min β+ 163Yb 1/2(+)
164Lu 71 93 163.94134(3) 3.14(3) min β+ 164Yb 1(-)
165Lu 71 94 164.939407(28) 10.74(10) min β+ 165Yb 1/2+
166Lu 71 95 165.93986(3) 2.65(10) min β+ 166Yb (6-)
166m1Lu 34.37(5) keV 1.41(10) min EC (58%) 166Yb 3(-)
IT (42%) 166Lu
166m2Lu 42.9(5) keV 2.12(10) min 0(-)
167Lu 71 96 166.93827(3) 51.5(10) min β+ 167Yb 7/2+
167mLu 0(30)# keV >1 min 1/2(-#)
168Lu 71 97 167.93874(5) 5.5(1) min β+ 168Yb (6-)
168mLu 180(110) keV 6.7(4) min β+ (95%) 168Yb 3+
IT (5%) 168Lu
169Lu 71 98 168.937651(6) 34.06(5) h β+ 169Yb 7/2+
169mLu 29.0(5) keV 160(10) s IT 169Lu 1/2-
170Lu 71 99 169.938475(18) 2.012(20) d β+ 170Yb 0+
170mLu 92.91(9) keV 670(100) ms IT 170Lu (4)-
171Lu 71 100 170.9379131(30) 8.24(3) d β+ 171Yb 7/2+
171mLu 71.13(8) keV 79(2) s IT 171Lu 1/2-
172Lu 71 101 171.939086(3) 6.70(3) d β+ 172Yb 4-
172m1Lu 41.86(4) keV 3.7(5) min IT 172Lu 1-
172m2Lu 65.79(4) keV 0.332(20) µs (1)+
172m3Lu 109.41(10) keV 440(12) µs (1)+
172m4Lu 213.57(17) keV 150 ns (6-)
173Lu 71 102 172.9389306(26) 1.37(1) a EC 173Yb 7/2+
173mLu 123.672(13) keV 74.2(10) µs 5/2-
174Lu 71 103 173.9403375(26) 3.31(5) a β+ 174Yb (1)-
174m1Lu 170.83(5) keV 142(2) d IT (99.38%) 174Lu 6-
EC (.62%) 174Yb
174m2Lu 240.818(4) keV 395(15) ns (3+)
174m3Lu 365.183(6) keV 145(3) ns (4-)
175Lu 71 104 174.9407718(23) Observationally Stable[n 4] 7/2+ 0.9741(2)
175m1Lu 1392.2(6) keV 984(30) µs (19/2+)
175m2Lu 353.48(13) keV 1.49(7) µs 5/2-
176Lu[n 5][n 6] 71 105 175.9426863(23) 38.5(7)×109 a β- 176Hf 7- 0.0259(2)
176mLu 122.855(6) keV 3.664(19) h β- (99.9%) 176Hf 1-
EC (.095%) 176Yb
177Lu 71 106 176.9437581(23) 6.6475(20) d β- 177Hf 7/2+
177m1Lu 150.3967(10) keV 130(3) ns 9/2-
177m2Lu 569.7068(16) keV 155(7) µs 1/2+
177m3Lu 970.1750(24) keV 160.44(6) d β- (78.3%) 177Hf 23/2-
IT (21.7%) 177Lu
177m4Lu 3900(10) keV 7(2) min
[6(+3-2) min]
39/2-
178Lu 71 107 177.945955(3) 28.4(2) min β- 178Hf 1(+)
178mLu 123.8(26) keV 23.1(3) min β- 178Hf 9(-)
179Lu 71 108 178.947327(6) 4.59(6) h β- 179Hf 7/2(+)
179mLu 592.4(4) keV 3.1(9) ms IT 179Lu 1/2(+)
180Lu 71 109 179.94988(8) 5.7(1) min β- 180Hf 5+
180m1Lu 13.9(3) keV ~1 s IT 180Lu 3-
180m2Lu 624.0(5) keV >=1 ms (9-)
181Lu 71 110 180.95197(32)# 3.5(3) min β- 181Hf (7/2+)
182Lu 71 111 181.95504(21)# 2.0(2) min β- 182Hf (0,1,2)
183Lu 71 112 182.95757(32)# 58(4) s β- 183Hf (7/2+)
184Lu 71 113 183.96091(43)# 20(3) s β- 184Hf (3+)
  1. ^ Bold for isotopes with half-lives longer than the age of the universe (nearly stable)
  2. ^ Abbreviations:
    EC: Electron capture
    IT: Isomeric transition
  3. ^ Bold for stable isotopes
  4. ^ Believed to undergo α decay to 171Tm
  5. ^ primordial radionuclide
  6. ^ Used in Lutetium-Hafnium dating

Notes

References

  1. ^ http://www.nucleonica.net/unc.aspx
Isotopes of ytterbium Isotopes of lutetium Isotopes of hafnium
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