# Isotopes of ytterbium

Naturally occurring ytterbium ($_{70}$Yb) is composed of seven stable isotopes: $^{168}$Yb, $^{170}$Yb–$^{174}$Yb, and $^{176}$Yb, with $^{174}$Yb being the most abundant (31.83% natural abundance). 30 radioisotopes have been characterized, with the most stable being $^{169}$Yb with a half-life of 32.014 days, $^{175}$Yb with a half-life of 4.185 days, and $^{166}$Yb with a half-life of 56.7 hours. All of the remaining radioactive isotopes have half-lives that are less than 2 hours, and the majority of these have half-lives that are less than 20 minutes. This element also has 18 meta states, with the most stable being $^{169m}$Yb (t$_{1/2}$ 46 seconds).
The isotopes of ytterbium range from $^{149}$Yb to $^{187}$Yb. The primary decay mode before the most abundant stable isotope, $^{174}$Yb is electron capture, and the primary mode after is beta emission. The primary decay products before $^{174}$Yb are isotopes of thulium, and the primary products after are isotopes of lutetium. Of interest to modern quantum optics, the different ytterbium isotopes follow either Bose–Einstein statistics or Fermi–Dirac statistics, leading to interesting behavior in optical lattices.

## List of isotopes

| Nuclide | Z | N | Isotopic mass (Da) | Half-life | Decay mode | Daughter isotope | Spin and parity | Natural abundance (mole fraction) | Natural abundance (mole fraction) |
| Nuclide | Excitation energy | Excitation energy | Excitation energy | Half-life | Decay mode | Daughter isotope | Spin and parity | Normal proportion | Range of variation |
| $^{149}$Yb | 70 | 79 | 148.96422(32)# | 0.7(2) s | β$^+$, p | $^{148}$Er | (1/2+) | | |
| $^{149}$Yb | 70 | 79 | 148.96422(32)# | 0.7(2) s | β$^+$ (rare) | $^{149}$Tm | (1/2+) | | |
| $^{150}$Yb | 70 | 80 | 149.95831(32)# | 700# ms [>200 ns] | β$^+$? | $^{150}$Tm? | 0+ | | |
| $^{151}$Yb | 70 | 81 | 150.95540(32) | 1.6(5) s | β$^+$ | $^{151}$Tm | (1/2+) | | |
| $^{151}$Yb | 70 | 81 | 150.95540(32) | 1.6(5) s | β$^+$, p (rare) | $^{150}$Er | (1/2+) | | |
| $^{151m1}$Yb | 740(100)# keV | 740(100)# keV | 740(100)# keV | 1.6(5) s | β$^+$ | $^{151}$Tm | (11/2−) | | |
| $^{151m1}$Yb | 740(100)# keV | 740(100)# keV | 740(100)# keV | 1.6(5) s | β$^+$, p (rare) | $^{150}$Er | (11/2−) | | |
| $^{151m2}$Yb | 2630(141)# keV | 2630(141)# keV | 2630(141)# keV | 2.6(7) μs | IT | $^{151}$Yb | 19/2−# | | |
| $^{151m3}$Yb | 3287(141)# keV | 3287(141)# keV | 3287(141)# keV | 20(1) μs | IT | $^{151}$Yb | 27/2−# | | |
| $^{152}$Yb | 70 | 82 | 151.95033(16) | 3.03(6) s | β$^+$ | $^{152}$Tm | 0+ | | |
| $^{152m}$Yb | 2744.5(10) keV | 2744.5(10) keV | 2744.5(10) keV | 30(1) μs | IT | $^{152}$Yb | (10+) | | |
| $^{153}$Yb | 70 | 83 | 152.94937(22)# | 4.2(2) s | β$^+$ | $^{153}$Tm | 7/2− | |
| $^{153}$Yb | 70 | 83 | 152.94937(22)# | 4.2(2) s | β$^+$, p (0.008%) | $^{152}$Er | 7/2− | |
| $^{153m}$Yb | 2630(50)# keV | 2630(50)# keV | 2630(50)# keV | 15(1) μs | IT | $^{153}$Yb | 27/2− | | |
| $^{154}$Yb | 70 | 84 | 153.946396(19) | 0.409(2) s | α (92.6%) | $^{150}$Er | 0+ | | |
| $^{154}$Yb | 70 | 84 | 153.946396(19) | 0.409(2) s | β$^+$ (7.4%) | $^{154}$Tm | 0+ | | |
| $^{155}$Yb | 70 | 85 | 154.945783(18) | 1.793(20) s | α (89%) | $^{151}$Er | (7/2−) | | |
| $^{155}$Yb | 70 | 85 | 154.945783(18) | 1.793(20) s | β$^+$ (11%) | $^{155}$Tm | (7/2−) | | |
| $^{156}$Yb | 70 | 86 | 155.942817(10) | 26.1(7) s | β$^+$ (90%) | $^{156}$Tm | 0+ | | |
| $^{156}$Yb | 70 | 86 | 155.942817(10) | 26.1(7) s | α (10%) | $^{152}$Er | 0+ | | |
| $^{157}$Yb | 70 | 87 | 156.942651(12) | 38.6(10) s | β$^+$ | $^{157}$Tm | 7/2− | | |
| $^{157}$Yb | 70 | 87 | 156.942651(12) | 38.6(10) s | α (rare) | $^{153}$Er | 7/2− | | |
| $^{158}$Yb | 70 | 88 | 157.939871(9) | 1.49(13) min | β$^+$ (99.99%) | $^{158}$Tm | 0+ | | |
| $^{158}$Yb | 70 | 88 | 157.939871(9) | 1.49(13) min | α (.0021%) | $^{154}$Er | 0+ | | |
| $^{159}$Yb | 70 | 89 | 158.940060(19) | 1.67(9) min | β$^+$ | $^{159}$Tm | 5/2− | | |
| $^{160}$Yb | 70 | 90 | 159.937559(6) | 4.8(2) min | β$^+$ | $^{160}$Tm | 0+ | | |
| $^{161}$Yb | 70 | 91 | 160.937912(16) | 4.2(2) min | β$^+$ | $^{161}$Tm | 3/2− | | |
| $^{162}$Yb | 70 | 92 | 161.935779(16) | 18.87(19) min | β$^+$ | $^{162}$Tm | 0+ | | |
| $^{163}$Yb | 70 | 93 | 162.936345(16) | 11.05(35) min | β$^+$ | $^{163}$Tm | 3/2− | | |
| $^{164}$Yb | 70 | 94 | 163.934501(16) | 75.8(17) min | EC | $^{164}$Tm | 0+ | | |
| $^{165}$Yb | 70 | 95 | 164.935270(28) | 9.9(3) min | β$^+$ | $^{165}$Tm | 5/2− | | |
| $^{165m}$Yb | 126.80(9) keV | 126.80(9) keV | 126.80(9) keV | 300(30) ns | IT | $^{165}$Yb | 9/2+ | | |
| $^{166}$Yb | 70 | 96 | 165.933876(8) | 56.7(1) h | EC | $^{166}$Tm | 0+ | | |
| $^{167}$Yb | 70 | 97 | 166.934954(4) | 17.5(2) min | β$^+$ | $^{167}$Tm | 5/2− | | |
| $^{167m}$Yb | 571.548(22) keV | 571.548(22) keV | 571.548(22) keV | ~180 ns | IT | $^{167}$Yb | 11/2− | | |
| $^{168}$Yb | 70 | 98 | 167.9338913(1) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.00123(3) | |
| $^{169}$Yb | 70 | 99 | 168.93518421(19) | 32.014(5) d | EC | $^{169}$Tm | 7/2+ | | |
| $^{169m}$Yb | 24.1999(16) keV | 24.1999(16) keV | 24.1999(16) keV | 46(2) s | IT | $^{169}$Yb | 1/2− | | |
| $^{170}$Yb | 70 | 100 | 169.934767243(11) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.02982(39) | |
| $^{170m}$Yb | 1258.46(14) keV | 1258.46(14) keV | 1258.46(14) keV | 370(15) ns | IT | $^{170}$Yb | 4− | | |
| $^{171}$Yb | 70 | 101 | 170.936331515(14) | Observationally Stable | Observationally Stable | Observationally Stable | 1/2− | 0.14086(140) | |
| $^{171m1}$Yb | 95.282(2) keV | 95.282(2) keV | 95.282(2) keV | 5.25(24) ms | IT | $^{171}$Yb | 7/2+ | | |
| $^{171m2}$Yb | 122.416(2) keV | 122.416(2) keV | 122.416(2) keV | 265(20) ns | IT | $^{171}$Yb | 5/2− | | |
| $^{172}$Yb | 70 | 102 | 171.936386654(15) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.21686(130) | |
| $^{172m}$Yb | 1550.43(6) keV | 1550.43(6) keV | 1550.43(6) keV | 3.6(1) μs | IT | $^{172}$Yb | 6− | | |
| $^{173}$Yb | 70 | 103 | 172.938216212(12) | Observationally Stable | Observationally Stable | Observationally Stable | 5/2− | 0.16103(63) | |
| $^{173m}$Yb | 398.9(5) keV | 398.9(5) keV | 398.9(5) keV | 2.9(1) μs | IT | $^{173}$Yb | 1/2− | | |
| $^{174}$Yb | 70 | 104 | 173.938867546(12) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.32025(80) | |
| $^{174m1}$Yb | 1518.148(13) keV | 1518.148(13) keV | 1518.148(13) keV | 830(40) μs | IT | $^{174}$Yb | 6+ | | |
| $^{174m2}$Yb | 1765.2(5) keV | 1765.2(5) keV | 1765.2(5) keV | 256(11) ns | IT | $^{174}$Yb | 7− | | |
| $^{175}$Yb | 70 | 105 | 174.94128191(8) | 4.185(1) d | β$^−$ | $^{175}$Lu | 7/2− | | |
| $^{175m}$Yb | 514.866(4) keV | 514.866(4) keV | 514.866(4) keV | 68.2(3) ms | IT | $^{175}$Yb | 1/2− | | |
| $^{176}$Yb | 70 | 106 | 175.942574706(16) | Observationally Stable | Observationally Stable | Observationally Stable | 0+ | 0.12995(83) | |
| $^{176m}$Yb | 1049.8(6) keV | 1049.8(6) keV | 1049.8(6) keV | 11.4(3) s | IT | $^{176}$Yb | 8− | | |
| $^{176m}$Yb | 1049.8(6) keV | 1049.8(6) keV | 1049.8(6) keV | 11.4(3) s | β$^−$ (<10#%) | $^{176}$Lu | 8− | | |
| $^{177}$Yb | 70 | 107 | 176.94526385(24) | 1.911(3) h | β$^−$ | $^{177}$Lu | 9/2+ | | |
| $^{177m}$Yb | 331.5(3) keV | 331.5(3) keV | 331.5(3) keV | 6.41(2) s | IT | $^{177}$Yb | 1/2− | | |
| $^{178}$Yb | 70 | 108 | 177.946669(7) | 74(3) min | β$^−$ | $^{178}$Lu | 0+ | | |
| $^{179}$Yb | 70 | 109 | 178.94993(22)# | 8.0(4) min | β$^−$ | $^{179}$Lu | (1/2−) | | |
| $^{180}$Yb | 70 | 110 | 179.95199(32)# | 2.4(5) min | β$^−$ | $^{180}$Lu | 0+ | | |
| $^{181}$Yb | 70 | 111 | 180.95589(32)# | 1# min [>300 ns] | β$^−$? | $^{181}$Lu? | 3/2−# | | |
| $^{182}$Yb | 70 | 112 | 181.95824(43)# | 30# s [>300 ns] | β$^−$? | $^{182}$Lu? | 0+ | | |
| $^{183}$Yb | 70 | 113 | 182.96243(43)# | 30# s [>300 ns] | β$^−$? | $^{183}$Lu? | 3/2−# | | |
| $^{184}$Yb | 70 | 114 | 183.96500(54)# | 7# s [>300 ns] | β$^−$? | $^{184}$Lu? | 0+ | | |
| $^{185}$Yb | 70 | 115 | 184.96943(54)# | 5# s [>300 ns] | β$^−$? | $^{185}$Lu? | 9/2−# | | |
| $^{186}$Yb | 70 | 116 | | | | | 0+ | | |
| $^{187}$Yb | 70 | 117 | | | | | | | |
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* ↑ However, all seven of the isotopes are observationally stable, meaning that they are predicted to be radioactive but decay has not been observed yet.
* ↑ $^m$Yb – Excited nuclear isomer.
* ↑ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
* ↑ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
* 1 2 3 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
* ↑ Modes of decay: EC:Electron capture IT:Isomeric transition
* ↑ Bold symbol as daughter – Daughter product is stable.
* ↑ Believed to undergo α decay to $^{164}$Er or β$^+$β$^+$ decay to $^{168}$Er with a half-life over 130×10$^{12}$ years
* ↑ Believed to undergo α decay to $^{166}$Er
* ↑ Believed to undergo α decay to $^{167}$Er
* ↑ Believed to undergo α decay to $^{168}$Er
* ↑ Believed to undergo α decay to $^{169}$Er
* ↑ Believed to undergo α decay to $^{170}$Er
* ↑ Believed to undergo α decay to $^{172}$Er or β$^−$β$^−$ decay to $^{176}$Hf with a half-life over 160×10$^{15}$ years
* ↑ Cluster decay daughter of $^{232}$Th