Isotopes of ytterbium

Naturally occurring Ytterbium (Yb) is composed of 7 stable isotopes, ¹⁶⁸Yb, ¹⁷⁰Yb, ¹⁷¹Yb, ¹⁷²Yb, ¹⁷³Yb, ¹⁷⁴Yb, and 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).

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.

Relative atomic mass: 173.045(10).^[1]

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)[2][n 1]	daughter isotope(s)[n 2]	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
^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 3]			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 4]			0+	0.0304(15)
^170mYb	1258.46(14) keV			370(15) ns			4−
^171Yb	70	101	170.9363258(26)	Observationally Stable[n 5]			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 6]			0+	0.2183(67)
^173Yb	70	103	172.9382108(26)	Observationally Stable[n 7]			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 8]			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 9]			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 10]	70	112

1. Abbreviations:
   EC: Electron capture
   IT: Isomeric transition
2. Bold for stable isotopes
3. Believed to undergo α decay to ¹⁶⁴Er or β⁺β⁺ decay to ¹⁶⁸Er with a half-life over 130×10¹² years
4. Believed to undergo α decay to ¹⁶⁶Er
5. Believed to undergo α decay to ¹⁶⁷Er
6. Believed to undergo α decay to ¹⁶⁸Er
7. Believed to undergo α decay to ¹⁶⁹Er
8. Believed to undergo α decay to ¹⁷⁰Er
9. Believed to undergo α decay to ¹⁷²Er or β⁻β⁻ decay to ¹⁷⁶Hf with a half-life over 160×10¹⁵ years
10. Decay Product of Thorium-232

Notes

• Geologically exceptional samples are known in which the isotopic composition lies outside the reported range. The uncertainty in the atomic mass may exceed the stated value for such specimens.
• Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
• Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.

References

1. Standard Atomic Weights 2015 – CIAAW
2. "Universal Nuclide Chart". nucleonica. (registration required (help)).

• Isotope masses from:
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). 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:
  • J. R. de Laeter; J. K. Böhlke; P. De Bièvre; H. Hidaka; H. S. Peiser; K. J. R. Rosman; P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683.
  • M. E. Wieser (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. See editing notes on this article's talk page.
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillonn (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
  • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
  • N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.