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Isotopes of holmium

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Isotopes of holmium (67Ho)
Main isotopes[1] Decay
abun­dance half-life (t1/2) mode pro­duct
163Ho synth 4570 y ε 163Dy
164Ho synth 28.8 min ε 164Dy
β 164Er
165Ho 100% stable
166Ho synth 26.812 h β 166Er
166m1Ho synth 1132.6 y β 166Er
167Ho synth 3.1 h β 167Er
Standard atomic weight Ar°(Ho)
Holmium-166m1 oxide

Natural holmium (67Ho) contains one observationally stable isotope, 165Ho. The below table lists 36 isotopes spanning 140Ho through 175Ho as well as 33 nuclear isomers. Among the known synthetic radioactive isotopes; the most stable one is 163Ho, with a half-life of 4,570 years. All other radioisotopes have half-lives not greater than 1.117 days in their ground states (although the metastable 166m1Ho has a half-life of about 1,200 years), and most have half-lives under 3 hours.

List of isotopes

[edit]


Nuclide
[n 1]
Z N Isotopic mass (Da)
[n 2][n 3]
Half-life
[n 4]
Decay
mode

[n 5]
Daughter
isotope

[n 6]
Spin and
parity
[n 7][n 4]
Isotopic
abundance
Excitation energy[n 4]
140Ho 67 73 139.96854(54)# 6(3) ms 8+#
141Ho 67 74 140.96310(54)# 4.1(3) ms (7/2−)
141mHo 66(2) keV 6.4(8) μs (1/2+)
142Ho 67 75 141.95977(54)# 400(100) ms β+ 142Dy (6 to 9)
p 141Dy
143Ho 67 76 142.95461(43)# 300# ms
[>200 ns]
β+ 143Dy 11/2−#
144Ho 67 77 143.95148(32)# 0.7(1) s β+ 144Dy
β+, p 143Tb
145Ho 67 78 144.94720(32)# 2.4(1) s β+ 145Dy (11/2−)
145mHo 100(100)# keV 100# ms 5/2+#
146Ho 67 79 145.94464(21)# 3.6(3) s β+ 146Dy (10+)
β+, p (rare) 145Tb
147Ho 67 80 146.94006(3) 5.8(4) s β+ 147Dy (11/2−)
β+, p (rare) 146Tb
148Ho 67 81 147.93772(14) 2.2(11) s β+ 148Dy (1+)
148m1Ho 400(100)# keV 9.49(12) s β+ (99.92%) 148Dy (6)−
β+, p (.08%) 147Tb
148m2Ho 690(100)# keV 2.35(4) ms (10+)
149Ho 67 82 148.933775(20) 21.1(2) s β+ 149Dy (11/2−)
149m1Ho 48.80(20) keV 56(3) s β+ 149Dy (1/2+)
149m2Ho 7200(350) keV >=100 ns
150Ho 67 83 149.933496(15) 76.8(18) s β+ 150Dy 2−
150m1Ho −10(50) keV 23.3(3) s β+ 150Dy (9)+
150m2Ho ~8000 keV 751 ns
151Ho 67 84 150.931688(13) 35.2(1) s β+ (78%) 151Dy 11/2(−)
α (22%) 147Tb
151mHo 41.0(2) keV 47.2(10) s α (77%) 147Tb 1/2(+)
β+ (22%) 151Dy
152Ho 67 85 151.931714(15) 161.8(3) s β+ (88%) 152Dy 2−
α (12%) 148Tb
152m1Ho 160(1) keV 50.0(4) s 9+
152m2Ho 3019.59(19) keV 8.4(3) μs 19−
153Ho 67 86 152.930199(6) 2.01(3) min β+ (99.94%) 153Dy 11/2−
α (.05%) 149Tb
153m1Ho 68.7(3) keV 9.3(5) min β+ (99.82%) 153Dy 1/2+
α (.18%) 149Tb
153m2Ho 2772 keV 229(2) ns (31/2+)
154Ho 67 87 153.930602(9) 11.76(19) min β+ (99.98%) 154Dy 2−
α (.02%) 150Tb
154mHo 238(30) keV 3.10(14) min β+ (99.99%) 154Dy 8+
α (.001%) 150Tb
IT (rare) 154Ho
155Ho 67 88 154.929103(19) 48(1) min β+ 155Dy 5/2+
155mHo 141.97(11) keV 880(80) μs 11/2−
156Ho 67 89 155.92984(5) 56(1) min β+ 156Dy 4−
156m1Ho 100(50)# keV 7.8(3) min β+ 156Dy (9+)
IT 156Ho
156m2Ho 52.4(5) keV 9.5(15) s 1−
157Ho 67 90 156.928256(26) 12.6(2) min β+ 157Dy 7/2−
158Ho 67 91 157.928941(29) 11.3(4) min β+ (93%) 158Dy 5+
α (7%) 154Tb
158m1Ho 67.200(10) keV 28(2) min IT (81%) 158Ho 2−
β+ (19%) 158Dy
158m2Ho 180(70)# keV 21.3(23) min (9+)
159Ho 67 92 158.927712(4) 33.05(11) min β+ 159Dy 7/2−
159mHo 205.91(5) keV 8.30(8) s IT 159Ho 1/2+
160Ho 67 93 159.928729(16) 25.6(3) min β+ 160Dy 5+
160m1Ho 59.98(3) keV 5.02(5) h IT (65%) 160Ho 2−
β+ (35%) 160Dy
160m2Ho 197(16) keV 3 s (9+)
161Ho 67 94 160.927855(3) 2.48(5) h EC 161Dy 7/2−
161mHo 211.16(3) keV 6.76(7) s IT 161Ho 1/2+
162Ho 67 95 161.929096(4) 15.0(10) min β+ 162Dy 1+
162mHo 106(7) keV 67.0(7) min IT (62%) 162Ho 6−
β+ (38%) 162Dy
163Ho 67 96 162.9287339(27) 4570(25) y EC 163Dy 7/2−
163mHo 297.88(7) keV 1.09(3) s IT 163Ho 1/2+
164Ho 67 97 163.9302335(30) 29(1) min EC (60%) 164Dy 1+
β (40%) 164Er
164mHo 139.77(8) keV 38.0(10) min
[37.5(+15−5) min]
IT 164Ho 6−
165Ho 67 98 164.9303221(27) Observationally Stable[n 8] 7/2− 1.0000
166Ho 67 99 165.9322842(27) 26.83(2) h β 166Er 0−
166m1Ho 5.985(18) keV 1200(180) y β 166Er (7)−
166m2Ho 190.9052(20) keV 185(15) μs 3+
167Ho 67 100 166.933133(6) 3.003(18) h β 167Er 7/2−
167mHo 259.34(11) keV 6.0(10) μs 3/2+
168Ho 67 101 167.93552(3) 2.99(7) min β 168Er 3+
168m1Ho 59(1) keV 132(4) s IT (99.5%) 168Ho (6+)
β (.5%) 168Er
168m2Ho 143.4(2) keV >4 μs (1)−
168m3Ho 192.6(2) keV 108(11) ns 1+
169Ho 67 102 168.936872(22) 4.72(10) min β 169Er 7/2−
170Ho 67 103 169.93962(5) 2.76(5) min β 170Er 6+#
170mHo 120(70) keV 43(2) s β 170Er (1+)
171Ho 67 104 170.94147(64) 53(2) s β 171Er 7/2−#
172Ho 67 105 171.94482(43)# 25(3) s β 172Er
173Ho 67 106 172.94729(43)# 10# s β 173Er 7/2−#
174Ho 67 107 173.95115(54)# 8# s
175Ho 67 108 174.95405(64)# 5# s 7/2−#
This table header & footer:
  1. ^ mHo – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ a b c # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  5. ^ Modes of decay:
    EC: Electron capture
    IT: Isomeric transition
  6. ^ Bold symbol as daughter – Daughter product is stable.
  7. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  8. ^ Believed to undergo α decay to 161Tb

References

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  1. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  2. ^ "Standard Atomic Weights: Holmium". CIAAW. 2021.
  3. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.