Isotopes of lutetium

Naturally occurring lutetium (₇₁Lu) is composed of one 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). Thirty-four 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 half an hour. This element also has 18 meta states, with the most stable being ^177mLu (t_1/2 160.4 days), ^174mLu (t_1/2 142 days) and ^178mLu (t_1/2 23.1 minutes).

Main isotopes of lutetium (₇₁Lu)

Iso­tope Decay abun­dance half-life (t1/2) mode pro­duct ^173Lu syn 1.37 y ε ^173Yb ^174Lu syn 3.31 y ε ^174Yb ^175Lu 97.401% stable ^176Lu 2.599% 3.78×10^10 y β^− ^176Hf
Standard atomic weight Ar, standard(Lu)	174.9668(1)[1]

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.

List of isotopes

Nuclide [n 1]	Z	N	Isotopic mass (Da) [n 2][n 3]	Half-life [n 4][n 5]	Decay mode [n 6]	Daughter isotope [n 7]	Spin and parity [n 8][n 5]	Natural abundance (mole fraction)
	Excitation energy[n 5]							Normal proportion	Range of variation
^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]	p	^149Yb	(1, 2)
^151Lu	71	80	150.96757682	80.6(5) ms	p (63.4%)	^150Yb	(11/2−)
					β^+ (36.6%)	^151Yb
^151mLu	77(5) keV			16(1) μs	p	^150Yb	(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	α (70%)	^149Tm	11/2−
					β^+ (30%)	^153Yb
^153m1Lu	80(5) keV			1# s	IT	^153Lu	1/2+
^153m2Lu	2502.5(4) keV			>0.1 μs	IT	^153Lu	23/2−
^153m3Lu	2632.9(5) keV			15(3) μs	IT	^153m2Lu	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) y	EC	^173Yb	7/2+
^173mLu	123.672(13) keV			74.2(10) μs			5/2−
^174Lu	71	103	173.9403375(26)	3.31(5) y	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 9]			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 10][n 11]	71	105	175.9426863(23)	38.5(7)×10^9 y	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. ^mLu – 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. Bold half-life – nearly stable, half-life longer than age of universe.
5. # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
6. Modes of decay:

   EC:	Electron capture
   IT:	Isomeric transition
   p:	Proton emission

7. Bold symbol as daughter – Daughter product is stable.
8. ( ) spin value – Indicates spin with weak assignment arguments.
9. Believed to undergo α decay to ¹⁷¹Tm
10. primordial radionuclide
11. Used in lutetium-hafnium dating

Lutetium-177

Radiopharmaceutical.

References

1. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.

• 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.