Thulium-154

Properties and data of the isotope ¹⁵⁴Tm.

Contents

General data

Name of the isotope:Thulium-154; Tm-154Symbol:¹⁵⁴Tm or 15469TmMass number A:154 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:85Isotopic mass:153.941570(15) u (atomic weight of Thulium-154)Nuclide mass:153.9037214 u (calculated nuclear mass without electrons)Mass excess:-54.42719 MeVMass defect:1.334875068 u (per nucleus)Nuclear binding energy:1243.42811659 MeV (per nucleus)
8.07420855 MeV (average binding energy per nucleon)Separation energy:S_N = 8.525(19) MeV (first neutron)
S_P = 1.247(17) MeV (first proton)Half-life:8.1(3) sDecay constant λ:0.085573725995055 s^-1Specific activity α:3.368215894456 × 10⁺²⁰ Bq g^-1
9103286201.2338 Ci g^-1Spin and parity:
(nuclear angular momentum)(2-)Magnetic dipole moment:μ(μ_N) = - 1.14(2)Quadrupole moment Q:+ 0.40(9) barn (100 fm²)Nuclear g-factor:g_l = -0.57Year of discovery:1964

Radioactive Decay

Half-life T_½ = 8.1(3) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁵⁴Er	46(5) %	8.178(15) MeV
α	¹⁵⁰Ho	54(5) %	5.0938(26) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁵⁴Yb, ¹⁵⁸Lu.

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^154mTm	70(50) keV	3.30(7) s	9+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 85) and isobaric (same nucleon number A = 154) with Thulium-154. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 85	Isobar A = 154
47	¹³²Ag
48	¹³³Cd
49	¹³⁴In
50	¹³⁵Sn
51	¹³⁶Sb
52	¹³⁷Te
53	¹³⁸I
54	¹³⁹Xe
55	¹⁴⁰Cs
56	¹⁴¹Ba
57	¹⁴²La	¹⁵⁴La
58	¹⁴³Ce	¹⁵⁴Ce
59	¹⁴⁴Pr	¹⁵⁴Pr
60	¹⁴⁵Nd	¹⁵⁴Nd
61	¹⁴⁶Pm	¹⁵⁴Pm
62	¹⁴⁷Sm	¹⁵⁴Sm
63	¹⁴⁸Eu	¹⁵⁴Eu
64	¹⁴⁹Gd	¹⁵⁴Gd
65	¹⁵⁰Tb	¹⁵⁴Tb
66	¹⁵¹Dy	¹⁵⁴Dy
67	¹⁵²Ho	¹⁵⁴Ho
68	¹⁵³Er	¹⁵⁴Er
69	¹⁵⁴Tm	¹⁵⁴Tm
70	¹⁵⁵Yb	¹⁵⁴Yb
71	¹⁵⁶Lu	¹⁵⁴Lu
72	¹⁵⁷Hf	¹⁵⁴Hf
73	¹⁵⁸Ta
74	¹⁵⁹W
75	¹⁶⁰Re
76	¹⁶¹Os