Isotopes of thulium

Isotopes of thulium (₆₉Tm)
Standard atomic weight Ar°(Tm)
	168.934219±0.000005; 168.93±0.01 (abridged);
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Last updated November 11, 2024

Naturally occurring thulium (₆₉Tm) is composed of one stable isotope, ¹⁶⁹Tm (100% natural abundance). Thirty-nine radioisotopes have been characterized, with the most stable being ¹⁷¹Tm with a half-life of 1.92 years, ¹⁷⁰Tm with a half-life of 128.6 days, ¹⁶⁸Tm with a half-life of 93.1 days, and ¹⁶⁷Tm with a half-life of 9.25 days. All of the remaining radioactive isotopes have half-lives that are less than 64 hours, and the majority of these have half-lives that are less than 2 minutes. This element also has 26 meta states, with the most stable being ^164mTm (t_1/2 5.1 minutes), ^160mTm (t_1/2 74.5 seconds) and ^155mTm (t_1/2 45 seconds).

The known isotopes of thulium range from ¹⁴⁴Tm to ¹⁸³Tm. The primary decay mode before the most abundant stable isotope, ¹⁶⁹Tm, is electron capture, and the primary mode after is beta emission. The primary decay products before ¹⁶⁹Tm are erbium isotopes, and the primary products after are ytterbium isotopes. All isotopes of thulium are either radioactive or, in the case of ¹⁶⁹Tm, observationally stable, meaning that ¹⁶⁹Tm is predicted to be radioactive but no actual decay has been observed.

List of isotopes

Nuclide ^{[n 1]}	Z	N	Isotopic mass (Da)^[4] ^{[n 2]}^{[n 3]}	Half-life ^[1] ^{[n 4]}	Decay mode ^[1] ^{[n 5]}	Daughter isotope ^{[n 6]}	Spin and parity ^[1] ^{[n 7]}^{[n 4]}	Isotopic abundance
Nuclide ^{[n 1]}	Excitation energy^{[n 4]}			Half-life ^[1] ^{[n 4]}	Decay mode ^[1] ^{[n 5]}	Daughter isotope ^{[n 6]}	Spin and parity ^[1] ^{[n 7]}^{[n 4]}	Isotopic abundance
¹⁴⁴Tm	69	75	143.97621(43)#	2.3(9) μs	p	¹⁴³Er	(10+)
¹⁴⁵Tm	69	76	144.97039(21)#	3.17(20) μs	p	¹⁴⁴Er	(11/2−)
¹⁴⁶Tm	69	77	145.96666(22)#	155(20) ms	p	¹⁴⁵Er	(1+)
^146m1Tm	304(6) keV			73(7) ms	p	¹⁴⁵Er	(5−)
^146m2Tm	437(7) keV			200(3) ms	p	¹⁴⁵Er	(10+)
¹⁴⁷Tm	69	78	146.9613799(73)	0.58(3) s	β⁺ (85%)	¹⁴⁷Er	11/2−
¹⁴⁷Tm	69	78	146.9613799(73)	0.58(3) s	p (15%)	¹⁴⁶Er	11/2−
^147mTm	62(5) keV			360(40) μs	p	¹⁴⁶Er	3/2+
¹⁴⁸Tm	69	79	147.958384(11)	0.7(2) s	β⁺	¹⁴⁸Er	(10+)
¹⁴⁹Tm	69	80	148.95283(22)#	0.9(2) s	β⁺ (99.74%)	¹⁴⁹Er	11/2−
¹⁴⁹Tm	69	80	148.95283(22)#	0.9(2) s	β⁺, p (0.26%)	¹⁴⁸Ho	11/2−
¹⁵⁰Tm	69	81	149.95009(21)#	3# s	β⁺	¹⁵⁰Er	(1+)
^150m1Tm^{[n 8]}	140(140)# keV			2.20(6) s	β⁺ (98.9%)	¹⁵⁰Er	(6−)
^150m1Tm^{[n 8]}	140(140)# keV			2.20(6) s	β⁺, p (1.1%)	¹⁴⁹Ho	(6−)
^150m2Tm	811(140)# keV			5.2(3) ms	IT	_150m1Tm	10+#
¹⁵¹Tm	69	82	150.945494(21)	4.17(11) s	β⁺	¹⁵¹Er	(11/2−)
^151m1Tm	93(6) keV			6.6(20) s	β⁺	¹⁵¹Er	(1/2+)
^151m2Tm	2655.67(22) keV			451(34) ns	IT	¹⁵¹Tm	(27/2−)
¹⁵²Tm	69	83	151.944476(58)	8.0(10) s	β⁺	¹⁵²Er	(2)−
^152m1Tm^{[n 8]}	−100(250) keV			5.2(6) s	β⁺	¹⁵²Er	(9)+
^152m2Tm	2455(250) keV			301(7) ns	IT	¹⁵²Tm	(17+)
¹⁵³Tm	69	84	152.942058(13)	1.48(1) s	α (91%)	¹⁴⁹Ho	(11/2−)
¹⁵³Tm	69	84	152.942058(13)	1.48(1) s	β⁺ (9%)	¹⁵³Er	(11/2−)
^153mTm	43.2(2) keV			2.5(2) s	α (92%)	¹⁴⁹Ho	(1/2+)
^153mTm	43.2(2) keV			2.5(2) s	β⁺ (8%)	¹⁵³Er	(1/2+)
¹⁵⁴Tm	69	85	153.941570(15)	8.1(3) s	β⁺ (54%)	¹⁵⁴Er	(2)−
¹⁵⁴Tm	69	85	153.941570(15)	8.1(3) s	α (46%)	¹⁵⁰Ho	(2)−
^154mTm^{[n 8]}	70(50) keV			3.30(7) s	α (58%)	¹⁵⁰Ho	(9)+
^154mTm^{[n 8]}	70(50) keV			3.30(7) s	β⁺ (42%)	¹⁵⁴Er	(9)+
¹⁵⁵Tm	69	86	154.939210(11)	21.6(2) s	β⁺ (99.17%)	¹⁵⁵Er	11/2−
¹⁵⁵Tm	69	86	154.939210(11)	21.6(2) s	α (0.83%)	¹⁵¹Ho	11/2−
^155mTm	41(6) keV			45(4) s	β⁺	¹⁵⁵Er	1/2+
¹⁵⁶Tm	69	87	155.938986(15)	83.8(18) s	β⁺ (99.94%)	¹⁵⁶Er	2−
¹⁵⁶Tm	69	87	155.938986(15)	83.8(18) s	α (0.064%)	¹⁵²Er	2−
^156mTm	400(200)# keV			~400 ns	IT	¹⁵⁶Tm	(11−)
¹⁵⁷Tm	69	88	156.936973(30)	3.63(9) min	β⁺	¹⁵⁷Er	1/2+
¹⁵⁷Tm	69	88	156.936973(30)	3.63(9) min	α (7.5×10⁻⁴%)	¹⁵³Er	1/2+
^157mTm^{[n 8]}	100(50)# keV			1.6 s			7/2−#
¹⁵⁸Tm	69	89	157.936980(27)	3.98(6) min	β⁺	¹⁵⁸Er	2−
^158mTm^{[n 8]}	100(50)# keV			~20 s			5−#
¹⁵⁹Tm	69	90	158.934975(30)	9.13(16) min	β⁺	¹⁵⁹Er	5/2+
¹⁶⁰Tm	69	91	159.935264(35)	9.4(3) min	β⁺	¹⁶⁰Er	1−
^160m1Tm	67(14) keV			74.5(15) s	IT (85%)	¹⁶⁰Tm	(5+)
^160m1Tm	67(14) keV			74.5(15) s	β⁺ (15%)	¹⁶⁰Er	(5+)
^160m2Tm	215(52)# keV			~200 ns	IT	¹⁶⁰Tm	(8)
¹⁶¹Tm	69	92	160.933549(30)	30.2(8) min	β⁺	¹⁶¹Er	7/2+
^161m1Tm	7.51(24) keV			5# min			(1/2+)
^161m2Tm	78.20(3) keV			110(3) ns	IT	¹⁶¹Tm	7/2−
¹⁶²Tm	69	93	161.934001(28)	21.70(19) min	β⁺	¹⁶²Er	1−
^162mTm	130(40) keV			24.3(17) s	IT (81%)	¹⁶²Tm	5+
^162mTm	130(40) keV			24.3(17) s	β⁺ (19%)	¹⁶²Er	5+
¹⁶³Tm	69	94	162.9326583(59)	1.810(5) h	β⁺	¹⁶³Er	1/2+
^163mTm	86.92(5) keV			380(30) ns	IT	¹⁶³Tm	(7/2)−
¹⁶⁴Tm	69	95	163.933538(27)	2.0(1) min	EC (61%)	¹⁶⁴Er	1+
¹⁶⁴Tm	69	95	163.933538(27)	2.0(1) min	β⁺ (39%)	¹⁶⁴Er	1+
^164mTm	20(12) keV			5.1(1) min	IT (~80%)	¹⁶⁴Tm	6−
^164mTm	20(12) keV			5.1(1) min	β⁺ (~20%)	¹⁶⁴Er	6−
¹⁶⁵Tm	69	96	164.9324418(18)	30.06(3) h	β⁺	¹⁶⁵Er	1/2+
^165m1Tm	80.37(6) keV			80(3) μs	IT	¹⁶⁵Tm	7/2+
^165m2Tm	160.47(6) keV			9.0(5) μs	IT	¹⁶⁵Tm	7/2−
¹⁶⁶Tm	69	97	165.933562(12)	7.70(3) h	β⁺	¹⁶⁶Er	2+
^166m1Tm	122(7) keV			348(21) ms	IT	¹⁶⁶Tm	(6−)
^166m2Tm	244(7) keV			2(1) μs	IT	¹⁶⁶Tm	(6−)
¹⁶⁷Tm	69	98	166.9328572(14)	9.25(2) d	EC	¹⁶⁷Er	1/2+
^167m1Tm	179.480(19) keV			1.16(6) μs	IT	¹⁶⁷Tm	7/2+
^167m2Tm	292.820(20) keV			0.9(1) μs	IT	¹⁶⁷Tm	7/2−
¹⁶⁸Tm	69	99	167.9341785(18)	93.1(2) d	β⁺ (99.99%)	¹⁶⁸Er	3+
¹⁶⁸Tm	69	99	167.9341785(18)	93.1(2) d	β⁻ (0.010%)	¹⁶⁸Yb	3+
¹⁶⁹Tm	69	100	168.93421896(79)	Observationally Stable ^{[n 9]}			1/2+	1.0000
^169mTm	316.1463(1) keV			659.9(23) ns	IT	¹⁶⁹Tm	7/2+
¹⁷⁰Tm	69	101	169.93580709(79)	128.6(3) d	β⁻ (99.87%)	¹⁷⁰Yb	1−
¹⁷⁰Tm	69	101	169.93580709(79)	128.6(3) d	EC (0.131%)	¹⁷⁰Er	1−
^170mTm	183.197(4) keV			4.12(13) μs	IT	¹⁷⁰Tm	3+
¹⁷¹Tm	69	102	170.9364352(10)	1.92(1) y	β⁻	¹⁷¹Yb	1/2+
^171m1Tm	424.9557(15) keV			2.60(2) μs	IT	¹⁷¹Tm	7/2−
^171m2Tm	1674.43(13) keV			1.7(2) μs	IT	¹⁷¹Tm	19/2+
¹⁷²Tm	69	103	171.9384070(59)	63.6(3) h	β⁻	¹⁷²Yb	2−
^172mTm	476.2(2) keV			132(7) μs	IT	¹⁷²Tm	(6+)
¹⁷³Tm	69	104	172.9396066(47)	8.24(8) h	β⁻	¹⁷³Yb	(1/2+)
^173m1Tm	317.73(20) keV			10.7(17) μs	IT	¹⁷³Tm	7/2−
^173m2Tm	1905.7(4) keV			250(69) ns	IT	¹⁷³Tm	19/2−
^173m3Tm	4047.9(5) keV			121(28) ns	IT	¹⁷³Tm	35/2−
¹⁷⁴Tm	69	105	173.942174(48)	5.4(1) min	β⁻	¹⁷⁴Yb	4−
^174m1Tm	252.4(7) keV			2.29(1) s	IT (>98.5%)	¹⁷⁴Tm	0+
^174m1Tm	252.4(7) keV			2.29(1) s	β⁻ (<1.5%)	¹⁷⁴Yb	0+
^174m2Tm	2091.7(3) keV			106(7) μs	IT	¹⁷⁴Tm	14−
¹⁷⁵Tm	69	106	174.943842(54)	15.2(5) min	β⁻	¹⁷⁵Yb	(1/2)+
^175m1Tm	440.0(11) keV			319(35) ns	IT	¹⁷⁵Tm	7/2−
^175m2Tm	1517.7(12) keV			21(14) μs	IT	¹⁷⁵Tm	23/2+
¹⁷⁶Tm	69	107	175.94700(11)	1.85(3) min	β⁻	¹⁷⁶Yb	(4+)
¹⁷⁷Tm	69	108	176.94893(22)#	95(7) s	β⁻	¹⁷⁷Yb	1/2+#
^177mTm^{[n 8]}	100(100)# keV			77(11) s	β⁻	¹⁷⁷Yb	7/2−#
¹⁷⁸Tm	69	109	177.95251(32)#	10# s [>300 ns]			1−#
¹⁷⁹Tm	69	110	178.95502(43)#	18# s [>300 ns]			1/2+#
¹⁸⁰Tm	69	111	179.95902(43)#	3# s [>300 ns]
¹⁸¹Tm	69	112	180.96195(54)#	7# s [>300 ns]			1/2+#
¹⁸²Tm^[5]	69	113	181.96619(54)#
¹⁸³Tm^[5]	69	114
This table header & footer: view

↑ ^mTm – 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
p: Proton emission
↑ Bold symbol as daughter – Daughter product is stable.
↑ ( ) spin value – Indicates spin with weak assignment arguments.
1 2 3 4 5 6 Order of ground state and isomer is uncertain.
↑ Believed to undergo α decay to ¹⁶⁵Ho

Thulium-170

Thulium-170 has a half-life of 128.6 days, decaying by β⁻ decay about 99.87% of the time and electron capture the remaining 0.13% of the time.^[1] Due to its low-energy X-ray emissions, it has been proposed for radiotherapy^[6] and as a source in a radiothermal generator.^[7]

Related Research Articles

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Po. Six isotopes of radon, ^{217, 218, 219, 220, 221, 222}Rn, occur in trace quantities in nature as decay products of, respectively, ²¹⁷At, ²¹⁸At, ²²³Ra, ²²⁴Ra, ²²⁵Ra, and ²²⁶Ra. ²¹⁷Rn and ²²¹Rn are produced in rare branches in the decay chain of trace quantities of ²³⁷Np; ²²²Rn is an intermediate step in the decay chain of ²³⁸U; ²¹⁹Rn is an intermediate step in the decay chain of ²³⁵U; and ²²⁰Rn occurs in the decay chain of ²³²Th.

There are 42 isotopes of polonium (₈₄Po). They range in size from 186 to 227 nucleons. They are all radioactive. ²¹⁰Po with a half-life of 138.376 days has the longest half-life of any naturally-occurring isotope of polonium and is the most common isotope of polonium. It is also the most easily synthesized polonium isotope. ²⁰⁹Po, which does not occur naturally, has the longest half-life of all isotopes of polonium at 124 years. ²⁰⁹Po can be made by using a cyclotron to bombard bismuth with protons, as can ²⁰⁸Po.

Thallium (₈₁Tl) has 41 isotopes with atomic masses that range from 176 to 216. ²⁰³Tl and ²⁰⁵Tl are the only stable isotopes and ²⁰⁴Tl is the most stable radioisotope with a half-life of 3.78 years. ²⁰⁷Tl, with a half-life of 4.77 minutes, has the longest half-life of naturally occurring Tl radioisotopes. All isotopes of thallium are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed.

Naturally occurring platinum (₇₈Pt) consists of five stable isotopes (¹⁹²Pt, ¹⁹⁴Pt, ¹⁹⁵Pt, ¹⁹⁶Pt, ¹⁹⁸Pt) and one very long-lived (half-life 4.83×10¹¹ years) radioisotope (¹⁹⁰Pt). There are also 34 known synthetic radioisotopes, the longest-lived of which is ¹⁹³Pt with a half-life of 50 years. All other isotopes have half-lives under a year, most under a day. All isotopes of platinum are either radioactive or observationally stable, meaning that they are predicted to be radioactive but no actual decay has been observed. Platinum-195 is the most abundant isotope.

Natural hafnium (₇₂Hf) consists of five observationally stable isotopes (¹⁷⁶Hf, ¹⁷⁷Hf, ¹⁷⁸Hf, ¹⁷⁹Hf, and ¹⁸⁰Hf) and one very long-lived radioisotope, ¹⁷⁴Hf, with a half-life of 7.0×10¹⁶ years. In addition, there are 34 known synthetic radioisotopes, the most stable of which is ¹⁸²Hf with a half-life of 8.9×10⁶ years. This extinct radionuclide is used in hafnium–tungsten dating to study the chronology of planetary differentiation.

Naturally occurring ytterbium (₇₀Yb) is composed of seven stable isotopes: ¹⁶⁸Yb, ¹⁷⁰Yb–¹⁷⁴Yb, and ¹⁷⁶Yb, with ¹⁷⁴Yb being the most abundant. 30 radioisotopes have been characterized, with the most stable being ¹⁶⁹Yb with a half-life of 32.014 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 18 meta states, with the most stable being ^169mYb.

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, and most have half-lives under 3 hours.

Naturally occurring terbium (₆₅Tb) is composed of one stable isotope, ¹⁵⁹Tb. Thirty-seven radioisotopes have been characterized, with the most stable being ¹⁵⁸Tb with a half-life of 180 years, ¹⁵⁷Tb with a half-life of 71 years, and ¹⁶⁰Tb with a half-life of 72.3 days. All of the remaining radioactive isotopes have half-lives that are less than 6.907 days, and the majority of these have half-lives that are less than 24 seconds. This element also has 27 meta states, with the most stable being ^156m1Tb, ^154m2Tb and ^154m1Tb.

Promethium (₆₁Pm) is an artificial element, except in trace quantities as a product of spontaneous fission of ²³⁸U and ²³⁵U and alpha decay of ¹⁵¹Eu, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. It was first synthesized in 1945.

Naturally occurring praseodymium (₅₉Pr) is composed of one stable isotope, ¹⁴¹Pr. Thirty-eight radioisotopes have been characterized with the most stable being ¹⁴³Pr, with a half-life of 13.57 days and ¹⁴²Pr, with a half-life of 19.12 hours. All of the remaining radioactive isotopes have half-lives that are less than six hours and the majority of these have half-lives that are less than 33 seconds. This element also has 15 meta states with the most stable being ^138mPr, ^142mPr and ^134mPr.

Naturally occurring lanthanum (₅₇La) is composed of one stable (¹³⁹La) and one radioactive (¹³⁸La) isotope, with the stable isotope, ¹³⁹La, being the most abundant (99.91% natural abundance). There are 39 radioisotopes that have been characterized, with the most stable being ¹³⁸La, with a half-life of 1.02×10¹¹ years; ¹³⁷La, with a half-life of 60,000 years and ¹⁴⁰La, with a half-life of 1.6781 days. The remaining radioactive isotopes have half-lives that are less than a day and the majority of these have half-lives that are less than 1 minute. This element also has 12 nuclear isomers, the longest-lived of which is ^132mLa, with a half-life of 24.3 minutes. Lighter isotopes mostly decay to isotopes of barium and heavy ones mostly decay to isotopes of cerium. ¹³⁸La can decay to both.

Antimony (₅₁Sb) occurs in two stable isotopes, ¹²¹Sb and ¹²³Sb. There are 37 artificial radioactive isotopes, the longest-lived of which are ¹²⁵Sb, with a half-life of 2.75856 years; ¹²⁴Sb, with a half-life of 60.2 days; and ¹²⁶Sb, with a half-life of 12.35 days. All other isotopes have half-lives less than 4 days, most less than an hour. There are also many isomers, the longest-lived of which is ^120m1Sb with a half-life of 5.76 days.

Naturally occurring cadmium (₄₈Cd) is composed of 8 isotopes. For two of them, natural radioactivity was observed, and three others are predicted to be radioactive but their decays have not been observed, due to extremely long half-lives. The two natural radioactive isotopes are ¹¹³Cd (beta decay, half-life is 8.04 × 10¹⁵ years) and ¹¹⁶Cd (two-neutrino double beta decay, half-life is 2.8 × 10¹⁹ years). The other three are ¹⁰⁶Cd, ¹⁰⁸Cd (double electron capture), and ¹¹⁴Cd (double beta decay); only lower limits on their half-life times have been set. Three isotopes—¹¹⁰Cd, ¹¹¹Cd, and ¹¹²Cd—are theoretically stable. Among the isotopes absent in natural cadmium, the most long-lived are ¹⁰⁹Cd with a half-life of 462.6 days, and ¹¹⁵Cd with a half-life of 53.46 hours. All of the remaining radioactive isotopes have half-lives that are less than 2.5 hours and the majority of these have half-lives that are less than 5 minutes. This element also has 12 known meta states, with the most stable being ^113mCd (t_1/2 14.1 years), ^115mCd (t_1/2 44.6 days) and ^117mCd (t_1/2 3.36 hours).

Naturally occurring rhodium (₄₅Rh) is composed of only one stable isotope, ¹⁰³Rh. The most stable radioisotopes are ¹⁰¹Rh with a half-life of 3.3 years, ¹⁰²Rh with a half-life of 207 days, and ⁹⁹Rh with a half-life of 16.1 days. Thirty other radioisotopes have been characterized with atomic weights ranging from 88.949 u (⁸⁹Rh) to 121.943 u (¹²²Rh). Most of these have half-lives that are less than an hour except ¹⁰⁰Rh and ¹⁰⁵Rh. There are also numerous meta states with the most stable being ^102mRh (0.141 MeV) with a half-life of about 3.7 years and ^101mRh (0.157 MeV) with a half-life of 4.34 days.

Arsenic (₃₃As) has 32 known isotopes and at least 10 isomers. Only one of these isotopes, ⁷⁵As, is stable; as such, it is considered a monoisotopic element. The longest-lived radioisotope is ⁷³As with a half-life of 80 days.

Naturally occurring manganese (₂₅Mn) is composed of one stable isotope, ⁵⁵Mn. Twenty-seven radioisotopes have been characterized, with the most stable being ⁵³Mn with a half-life of 3.7 million years, ⁵⁴Mn with a half-life of 312.3 days, and ⁵²Mn with a half-life of 5.591 days. All of the remaining radioactive isotopes have half-lives that are less than 3 hours and the majority of these have half-lives that are less than a minute. This element also has seven meta states.

Naturally occurring vanadium (₂₃V) is composed of one stable isotope ⁵¹V and one radioactive isotope ⁵⁰V with a half-life of 2.71×10¹⁷ years. 24 artificial radioisotopes have been characterized (in the range of mass number between 40 and 65) with the most stable being ⁴⁹V with a half-life of 330 days, and ⁴⁸V with a half-life of 15.9735 days. All of the remaining radioactive isotopes have half-lives shorter than an hour, the majority of them below 10 seconds, the least stable being ⁴²V with a half-life shorter than 55 nanoseconds, with all of the isotopes lighter than it, and none of the heavier, have unknown half-lives. In 4 isotopes, metastable excited states were found (including 2 metastable states for ⁶⁰V), which adds up to 5 meta states.

Naturally occurring scandium (₂₁Sc) is composed of one stable isotope, ⁴⁵Sc. Twenty-seven radioisotopes have been characterized, with the most stable being ⁴⁶Sc with a half-life of 83.8 days, ⁴⁷Sc with a half-life of 3.35 days, and ⁴⁸Sc with a half-life of 43.7 hours and ⁴⁴Sc with a half-life of 3.97 hours. All the remaining isotopes have half-lives that are less than four hours, and the majority of these have half-lives that are less than two minutes, the least stable being proton unbound ³⁹Sc with a half-life shorter than 300 nanoseconds. This element also has 13 meta states with the most stable being ^44m2Sc.

Einsteinium (₉₉Es) is a synthetic element, and thus a standard atomic weight cannot be given. Like all synthetic elements, it has no stable isotopes. The first isotope to be discovered was ²⁵³Es in 1952. There are 18 known radioisotopes from ²⁴⁰Es to ²⁵⁷Es, and 4 nuclear isomers. The longest-lived isotope is ²⁵²Es with a half-life of 471.7 days, or around 1.293 years.

Mendelevium (₁₀₁Md) is a synthetic element, and thus a standard atomic weight cannot be given. Like all artificial elements, it has no stable isotopes. The first isotope to be synthesized was ²⁵⁶Md in 1955. There are 17 known radioisotopes, ranging in atomic mass from ²⁴⁴Md to ²⁶⁰Md, and 5 isomers. The longest-lived isotope is ²⁵⁸Md with a half-life of 51.3 days, and the longest-lived isomer is ^258mMd with a half-life of 57 minutes.

References

1 2 3 4 5 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.
↑ "Standard Atomic Weights: Thulium". CIAAW. 2021.
↑ 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.
↑ Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.
1 2 Tarasov, O. B.; Gade, A.; Fukushima, K.; et al. (2024). "Observation of New Isotopes in the Fragmentation of ¹⁹⁸Pt at FRIB". Physical Review Letters. 132 (072501). doi:10.1103/PhysRevLett.132.072501.
↑ Polyak, Andras; Das, Tapas; Chakraborty, Sudipta; Kiraly, Reka; Dabasi, Gabriella; Joba, Robert Peter; Jakab, Csaba; Thuroczy, Julianna; Postenyi, Zita; Haasz, Veronika; Janoki, Gergely; Janoki, Gyozo A.; Pillai, Maroor R.A.; Balogh, Lajos (October 2014). "Thulium-170-Labeled Microparticles for Local Radiotherapy: Preliminary Studies". Cancer Biotherapy and Radiopharmaceuticals. 29 (8): 330–338. doi:10.1089/cbr.2014.1680. ISSN 1084-9785. PMID 25226213 – via Academia.edu.
↑ Dustin, J. Seth; Borrelli, R.A. (December 2021). "Assessment of alternative radionuclides for use in a radioisotope thermoelectric generator". Nuclear Engineering and Design. 385: 111475. doi: 10.1016/j.nucengdes.2021.111475 .

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
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.

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[4] Tm – Excited nuclear isomer.

[6] ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.

[TMS-7] # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).

[TNN-8] 1 2 3 # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).

[9] Modes of decay:
EC: Electron capture
IT: Isomeric transition
p: Proton emission

[10] Bold symbol as daughter – Daughter product is stable.

[11] ( ) spin value – Indicates spin with weak assignment arguments.

[order-12] 1 2 3 4 5 6 Order of ground state and isomer is uncertain.

[13] Believed to undergo α decay to ¹⁶⁵Ho

[NUBASE2020-1] 1 2 3 4 5 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: Thulium". CIAAW. 2021.

[CIAAW2021-3] 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.

[AME2020_II-5] Wang, Meng; Huang, W.J.; Kondev, F.G.; Audi, G.; Naimi, S. (2021). "The AME 2020 atomic mass evaluation (II). Tables, graphs and references*". Chinese Physics C. 45 (3): 030003. doi:10.1088/1674-1137/abddaf.

[PRL132.7-14] 1 2 Tarasov, O. B.; Gade, A.; Fukushima, K.; et al. (2024). "Observation of New Isotopes in the Fragmentation of ¹⁹⁸Pt at FRIB". Physical Review Letters. 132 (072501). doi:10.1103/PhysRevLett.132.072501.

[polyak2014-15] Polyak, Andras; Das, Tapas; Chakraborty, Sudipta; Kiraly, Reka; Dabasi, Gabriella; Joba, Robert Peter; Jakab, Csaba; Thuroczy, Julianna; Postenyi, Zita; Haasz, Veronika; Janoki, Gergely; Janoki, Gyozo A.; Pillai, Maroor R.A.; Balogh, Lajos (October 2014). "Thulium-170-Labeled Microparticles for Local Radiotherapy: Preliminary Studies". Cancer Biotherapy and Radiopharmaceuticals. 29 (8): 330–338. doi:10.1089/cbr.2014.1680. ISSN 1084-9785. PMID 25226213 – via Academia.edu.

[dustin2021-16] Dustin, J. Seth; Borrelli, R.A. (December 2021). "Assessment of alternative radionuclides for use in a radioisotope thermoelectric generator". Nuclear Engineering and Design. 385: 111475. doi: 10.1016/j.nucengdes.2021.111475 .

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[n 2]

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Isotopes of thulium

Contents

List of isotopes

Thulium-170

Related Research Articles

References