Thulium-159

Properties and data of the isotope ¹⁵⁹Tm.

Contents

General data

Name of the isotope:Thulium-159; Tm-159Symbol:¹⁵⁹Tm or 15969TmMass number A:159 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:90Isotopic mass:158.93497(3) u (atomic weight of Thulium-159)Nuclide mass:158.8971214 u (calculated nuclear mass without electrons)Mass excess:-60.57505 MeVMass defect:1.384799648 u (per nucleus)Nuclear binding energy:1289.93256331 MeV (per nucleus)
8.11278342 MeV (average binding energy per nucleon)Separation energy:S_N = 9.94(4) MeV (first neutron)
S_P = 2.56(4) MeV (first proton)Half-life:9.13(16) minDecay constant λ:0.0012653289166848 s^-1Specific activity α:4.822777829384 × 10⁺¹⁸ Bq g^-1
130345346.74012 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μ_N) = + 3.42(3)Quadrupole moment Q:+ 1.93(7) barn (100 fm²)Nuclear g-factor:g_l = 1.368Charge radius:5.1392(60) femtometer fmYear of discovery:1971

Radioactive Decay

Half-life T_½ = 9.13(16) min (minutes) respectively 5.478 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁵⁹Er	100 %	3.991(28) MeV

Parent Nuclides

Direct parent isotope is: ¹⁵⁹Yb.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 90) and isobaric (same nucleon number A = 159) with Thulium-159. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 90	Isobar A = 159
51	¹⁴¹Sb
52	¹⁴²Te
53	¹⁴³I
54	¹⁴⁴Xe
55	¹⁴⁵Cs
56	¹⁴⁶Ba
57	¹⁴⁷La
58	¹⁴⁸Ce
59	¹⁴⁹Pr	¹⁵⁹Pr
60	¹⁵⁰Nd	¹⁵⁹Nd
61	¹⁵¹Pm	¹⁵⁹Pm
62	¹⁵²Sm	¹⁵⁹Sm
63	¹⁵³Eu	¹⁵⁹Eu
64	¹⁵⁴Gd	¹⁵⁹Gd
65	¹⁵⁵Tb	¹⁵⁹Tb
66	¹⁵⁶Dy	¹⁵⁹Dy
67	¹⁵⁷Ho	¹⁵⁹Ho
68	¹⁵⁸Er	¹⁵⁹Er
69	¹⁵⁹Tm	¹⁵⁹Tm
70	¹⁶⁰Yb	¹⁵⁹Yb
71	¹⁶¹Lu	¹⁵⁹Lu
72	¹⁶²Hf	¹⁵⁹Hf
73	¹⁶³Ta	¹⁵⁹Ta
74	¹⁶⁴W	¹⁵⁹W
75	¹⁶⁵Re	¹⁵⁹Re
76	¹⁶⁶Os
77	¹⁶⁷Ir
78	¹⁶⁸Pt