Isotopes of thulium

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Naturally occurring thulium (Tm) is composed of 1 stable isotope, 169Tm (100% natural abundance). 34 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 (t1/2 5.1 minutes), 160mTm (t1/2 74.5 seconds) and 155mTm (t1/2 45 seconds).

The isotopes of thulium range in atomic weight from 144.97007 u (145Tm) to 178.95534 u (179Tm). 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.

Standard atomic mass: 168.93421(2) u

Table[edit]

nuclide
symbol
Z(p) N(n)  
isotopic mass (u)
 
half-life decay
mode(s)[1][n 1]
daughter
isotope(s)[n 2]
nuclear
spin
representative
isotopic
composition
(mole fraction)
range of natural
variation
(mole fraction)
excitation energy
145Tm 69 76 144.97007(43)# 3.1(3) µs (11/2-)
146Tm 69 77 145.96643(43)# 240(30) ms p 145Er (6-)
β+ (rare) 146Er
146mTm 71(6) keV 72(23) ms p 145Er (10+)
β+ (rare) 146Er
147Tm 69 78 146.96096(32)# 0.58(3) s β+ (85%) 147Er 11/2-
p (15%) 146Er
147mTm 60(5) keV 360(40) µs 3/2+
148Tm 69 79 147.95784(43)# 0.7(2) s β+ 148Er (10+)
148mTm 0.7 s
149Tm 69 80 148.95272(32)# 0.9(2) s β+ (99.74%) 149Er (11/2-)
β+, p (.26%) 148Ho
150Tm 69 81 149.94996(21)# 3# s β+ 150Er (1+)
150m1Tm 140(140)# keV 2.20(6) s β+ (98.8%) 150Er (6-)
β+, p (1.2%) 149Ho
150m2Tm 810(140)# keV 5.2(3) ms (10+)
151Tm 69 82 150.945483(22) 4.17(10) s β+ 151Er (11/2-)
151m1Tm 92(7) keV 6.6(14) s β+ 151Er (1/2+)
151m2Tm 2655.67(22) keV 451(24) ns (27/2-)
152Tm 69 83 151.94442(8) 8.0(10) s β+ 152Er (2#)-
152m1Tm 100(80)# keV 5.2(6) s β+ 152Er (9)+
152m2Tm 2555.05(19)+X keV 294(12) ns (17+)
153Tm 69 84 152.942012(20) 1.48(1) s α (91%) 149Ho (11/2-)
β+ (9%) 153Er
153mTm 43.2(2) keV 2.5(2) s α (92%) 149Ho (1/2+)
β+ (8%) 153Er
154Tm 69 85 153.941568(15) 8.1(3) s β+ (56%) 154Er (2-)
α (44%) 150Ho
154mTm 70(50) keV 3.30(7) s α (90%) 150Ho (9+)
β+ (10%) 154Er
155Tm 69 86 154.939199(14) 21.6(2) s β+ (98.1%) 155Er (11/2-)
α (1.9%) 151Ho
155mTm 41(6) keV 45(3) s β+ (92%) 155Er (1/2+)
α (8%) 151Ho
156Tm 69 87 155.938980(17) 83.8(18) s β+ (99.93%) 156Er 2-
α (.064%) 152Er
156mTm 203.6(5) keV ~400 ns (11-)
157Tm 69 88 156.93697(3) 3.63(9) min β+ 157Er 1/2+
158Tm 69 89 157.936980(27) 3.98(6) min β+ 158Er 2-
158mTm 50(100)# keV ~20 ns (5+)
159Tm 69 90 158.93498(3) 9.13(16) min β+ 159Er 5/2+
160Tm 69 91 159.93526(4) 9.4(3) min β+ 160Er 1-
160m1Tm 70(20) keV 74.5(15) s IT (85%) 160Tm 5(+#)
β+ (15%) 160Er
160m2Tm 98.2+X keV ~200 ns (8)
161Tm 69 92 160.93355(3) 30.2(8) min β+ 161Er 7/2+
161m1Tm 7.4(2) keV 5# min 1/2+
161m2Tm 78.20(3) keV 110(3) ns 7/2-
162Tm 69 93 161.933995(28) 21.70(19) min β+ 162Er 1-
162mTm 130(40) keV 24.3(17) s IT (82%) 162Tm 5+
β+ (18%) 162Er
163Tm 69 94 162.932651(6) 1.810(5) h β+ 163Er 1/2+
164Tm 69 95 163.93356(3) 2.0(1) min β+ 164Er 1+
164mTm 10(6) keV 5.1(1) min IT (80%) 164Tm 6-
β+ (20%) 164Er
165Tm 69 96 164.932435(4) 30.06(3) h β+ 165Er 1/2+
166Tm 69 97 165.933554(13) 7.70(3) h β+ 166Er 2+
166mTm 122(8) keV 340(25) ms IT 166Tm 6-
167Tm 69 98 166.9328516(29) 9.25(2) d EC 167Er 1/2+
167m1Tm 179.480(19) keV 1.16(6) µs (7/2)+
167m2Tm 292.820(20) keV 0.9(1) µs 7/2-
168Tm 69 99 167.934173(3) 93.1(2) d β+ (99.99%) 168Er 3+
β- (.01%) 168Yb
169Tm 69 100 168.9342133(27) Observationally Stable[n 3] 1/2+ 1.0000
170Tm 69 101 169.9358014(27) 128.6(3) d β- (99.86%) 170Yb 1-
EC (.14%) 170Er
170mTm 183.197(4) keV 4.12(13) µs (3)+
171Tm 69 102 170.9364294(28) 1.92(1) a β- 171Yb 1/2+
171mTm 424.9560(15) keV 2.60(2) µs 7/2-
172Tm 69 103 171.938400(6) 63.6(2) h β- 172Yb 2-
173Tm 69 104 172.939604(5) 8.24(8) h β- 173Yb (1/2+)
173mTm 317.73(20) keV 10(3) µs (7/2-)
174Tm 69 105 173.94217(5) 5.4(1) min β- 174Yb (4)-
175Tm 69 106 174.94384(5) 15.2(5) min β- 175Yb (1/2+)
176Tm 69 107 175.94699(11) 1.85(3) min β- 176Yb (4+)
177Tm 69 108 176.94904(32)# 90(6) s β- 177Yb (7/2-)
178Tm 69 109 177.95264(43)# 30# s β- 178Yb
179Tm 69 110 178.95534(54)# 20# s β- 179Yb 1/2+#
  1. ^ Abbreviations:
    EC: Electron capture
    IT: Isomeric transition
  2. ^ Bold for stable isotopes
  3. ^ Believed to undergo α decay to 165Ho

Notes[edit]

  • 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[edit]

  1. ^ http://www.nucleonica.net/unc.aspx


Isotopes of erbium Isotopes of thulium Isotopes of ytterbium
Table of nuclides