Isotopes of ytterbium

Naturally occurring ytterbium (₇₀Yb) is composed of 7 stable isotopes, ¹⁶⁸Yb–¹⁷⁶Yb, with ¹⁷⁴Yb being the most abundant (31.83% natural abundance). Twenty-seven radioisotopes have been characterized, with the most stable being ¹⁶⁹Yb with a half-life of 32.026 days, ¹⁷⁵Yb with a half-life of 4.185 days, and ¹⁶⁶Yb 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 12 meta states, with the most stable being ^169mYb (t_1/2 46 seconds).

Main isotopes of ytterbium (₇₀Yb)

Iso­tope Decay abun­dance half-life (t1/2) mode pro­duct ^166Yb syn 56.7 h ε ^166Tm ^168Yb 0.126% stable ^169Yb syn 32.026 d ε ^169Tm ^170Yb 3.023% stable ^171Yb 14.216% stable ^172Yb 21.754% stable ^173Yb 16.098% stable ^174Yb 31.896% stable ^175Yb syn 4.185 d β^− ^175Lu ^176Yb 12.887% stable ^177Yb syn 1.911 h β^− ^177Lu
Standard atomic weight Ar, standard(Yb)	173.045(10)[1][2]

The isotopes of ytterbium range in atomic weight from 147.967 u (¹⁴⁸Yb) to 180.9562 u (¹⁸¹Yb). The primary decay mode before the most abundant stable isotope, ¹⁷⁴Yb is electron capture, and the primary mode after is beta emission. The primary decay products before ¹⁷⁴Yb 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 [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 4]	Natural abundance (mole fraction)
	Excitation energy[n 4]							Normal proportion	Range of variation
^148Yb	70	78	147.96742(64)#	250# ms	β^+	^148Tm	0+
^149Yb	70	79	148.96404(54)#	0.7(2) s	β^+	^149Tm	(1/2+, 3/2+)
^150Yb	70	80	149.95842(43)#	700# ms [>200 ns]	β^+	^150Tm	0+
^151Yb	70	81	150.95540(32)	1.6(5) s	β^+	^151Tm	(1/2+)
					β^+, p (rare)	^150Er
^151m1Yb	750(100)# keV			1.6(5) s	β^+	^151Tm	(11/2−)
					β^+, p (rare)	^150Er
^151m2Yb	1790(500)# keV			2.6(7) μs			19/2−#
^151m3Yb	2450(500)# keV			20(1) μs			27/2−#
^152Yb	70	82	151.95029(22)	3.04(6) s	β^+	^152Tm	0+
					β^+, p (rare)	^151Er
^153Yb	70	83	152.94948(21)#	4.2(2) s	α (50%)	^149Er	7/2−#
					β^+ (50%)	^153Tm
					β^+, p (.008%)	^152Er
^153mYb	2700(100) keV			15(1) μs			(27/2−)
^154Yb	70	84	153.946394(19)	0.409(2) s	α (92.8%)	^150Er	0+
					β^+ (7.119%)	^154Tm
^155Yb	70	85	154.945782(18)	1.793(19) s	α (89%)	^151Er	(7/2−)
					β^+ (11%)	^155Tm
^156Yb	70	86	155.942818(12)	26.1(7) s	β^+ (90%)	^156Tm	0+
					α (10%)	^152Er
^157Yb	70	87	156.942628(11)	38.6(10) s	β^+ (99.5%)	^157Tm	7/2−
					α (.5%)	^153Er
^158Yb	70	88	157.939866(9)	1.49(13) min	β^+ (99.99%)	^158Tm	0+
					α (.0021%)	^154Er
^159Yb	70	89	158.94005(2)	1.67(9) min	β^+	^159Tm	5/2(−)
^160Yb	70	90	159.937552(18)	4.8(2) min	β^+	^160Tm	0+
^161Yb	70	91	160.937902(17)	4.2(2) min	β^+	^161Tm	3/2−
^162Yb	70	92	161.935768(17)	18.87(19) min	β^+	^162Tm	0+
^163Yb	70	93	162.936334(17)	11.05(25) min	β^+	^163Tm	3/2−
^164Yb	70	94	163.934489(17)	75.8(17) min	EC	^164Tm	0+
^165Yb	70	95	164.93528(3)	9.9(3) min	β^+	^165Tm	5/2−
^166Yb	70	96	165.933882(9)	56.7(1) h	EC	^166Tm	0+
^167Yb	70	97	166.934950(5)	17.5(2) min	β^+	^167Tm	5/2−
^168Yb	70	98	167.933897(5)	Observationally Stable[n 7]			0+	0.0013(1)
^169Yb	70	99	168.935190(5)	32.026(5) d	EC	^169Tm	7/2+
^169mYb	24.199(3) keV			46(2) s	IT	^169Yb	1/2−
^170Yb	70	100	169.9347618(26)	Observationally Stable[n 8]			0+	0.0304(15)
^170mYb	1258.46(14) keV			370(15) ns			4−
^171Yb	70	101	170.9363258(26)	Observationally Stable[n 9]			1/2−	0.1428(57)
^171m1Yb	95.282(2) keV			5.25(24) ms	IT	^171Yb	7/2+
^171m2Yb	122.416(2) keV			265(20) ns			5/2−
^172Yb	70	102	171.9363815(26)	Observationally Stable[n 10]			0+	0.2183(67)
^173Yb	70	103	172.9382108(26)	Observationally Stable[n 11]			5/2−	0.1613(27)
^173mYb	398.9(5) keV			2.9(1) μs			1/2−
^174Yb	70	104	173.9388621(26)	Observationally Stable[n 12]			0+	0.3183(92)
^175Yb	70	105	174.9412765(26)	4.185(1) d	β^−	^175Lu	7/2−
^175mYb	514.865(4) keV			68.2(3) ms			1/2−
^176Yb	70	106	175.9425717(28)	Observationally Stable[n 13]			0+	0.1276(41)
^176mYb	1050.0(3) keV			11.4(3) s			(8)−
^177Yb	70	107	176.9452608(28)	1.911(3) h	β^−	^177Lu	(9/2+)
^177mYb	331.5(3) keV			6.41(2) s	IT	^177Yb	(1/2−)
^178Yb	70	108	177.946647(11)	74(3) min	β^−	^178Lu	0+
^179Yb	70	109	178.95017(32)#	8.0(4) min	β^−	^179Lu	(1/2−)
^180Yb	70	110	179.95233(43)#	2.4(5) min	β^−	^180Lu	0+
^181Yb	70	111	180.95615(43)#	1# min	β^−	^181Lu	3/2−#
^182Yb[n 14]	70	112		> 160 ns	β^−	^182Lu	0+

1. ^mYb – 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. # – 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. Believed to undergo α decay to ¹⁶⁴Er or β⁺β⁺ decay to ¹⁶⁸Er with a half-life over 130×10¹² years
8. Believed to undergo α decay to ¹⁶⁶Er
9. Believed to undergo α decay to ¹⁶⁷Er
10. Believed to undergo α decay to ¹⁶⁸Er
11. Believed to undergo α decay to ¹⁶⁹Er
12. Believed to undergo α decay to ¹⁷⁰Er
13. Believed to undergo α decay to ¹⁷²Er or β⁻β⁻ decay to ¹⁷⁶Hf with a half-life over 160×10¹⁵ years
14. Cluster decay daughter of ²³²Th

References

1. "Standard Atomic Weights 2015". Commission on Isotopic Abundances and Atomic Weights. 12 October 2015. Retrieved 18 February 2017.
2. "Standard Atomic Weight of Ytterbium Revised". Chemistry International. October 2015. p. 26. doi:10.1515/ci-2015-0512. eISSN 0193-6484. ISSN 0193-6484.

• Isotope masses from:
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
• Isotopic compositions and standard atomic masses from:
  • de Laeter, John Robert; Böhlke, John Karl; De Bièvre, Paul; Hidaka, Hiroshi; Peiser, H. Steffen; Rosman, Kevin J. R.; Taylor, Philip D. P. (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry. 75 (6): 683–800. doi:10.1351/pac200375060683.
  • Wieser, Michael E. (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry. 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
• Half-life, spin, and isomer data selected from the following sources.
  • Audi, Georges; Bersillon, Olivier; Blachot, Jean; Wapstra, Aaldert Hendrik (2003), "The NUBASE evaluation of nuclear and decay properties", Nuclear Physics A, 729: 3–128, Bibcode:2003NuPhA.729....3A, doi:10.1016/j.nuclphysa.2003.11.001
  • National Nuclear Data Center. "NuDat 2.x database". Brookhaven National Laboratory.
  • Holden, Norman E. (2004). "11. Table of the Isotopes". In Lide, David R. (ed.). CRC Handbook of Chemistry and Physics (85th ed.). Boca Raton, Florida: CRC Press. ISBN 978-0-8493-0485-9.