Thulium-166m

Properties and data of the isotope ^166mTm.

Contents

General data

Name of the isotope:Thulium-166m; Tm-166mSymbol:^166mTm or 166m69TmMass number A:166 (= number of nucleons)Atomic number Z:69 (= number of protons)Neutrons N:97Isotopic mass:165.933560(12) u (atomic weight of Thulium-166m)
Excitation energy: 109+x keVNuclide mass:165.8957114 u (calculated nuclear mass without electrons)Mass excess:-61.88846 MeVMass defect:1.44686406 u (per nucleus)Nuclear binding energy:1347.74519071 MeV (per nucleus)
8.11894693 MeV (average binding energy per nucleon)Half-life:340(25) msDecay constant λ:2.0386681781175 s^-1Specific activity α:7.440695112299 × 10⁺²¹ Bq g^-1
201099867899.99 Ci g^-1Spin and parity:
(nuclear angular momentum)(6-)

Radioactive Decay

Half-life T_½ = 340(25) ms respectively 3.40 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	¹⁶⁶Tm	100 %

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
¹⁶⁶Tm		7.70(3) h	2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 97) and isobaric (same nucleon number A = 166) with Thulium-166m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 97	Isobar A = 166
56	¹⁵³Ba
57	¹⁵⁴La
58	¹⁵⁵Ce
59	¹⁵⁶Pr
60	¹⁵⁷Nd
61	¹⁵⁸Pm
62	¹⁵⁹Sm	¹⁶⁶Sm
63	¹⁶⁰Eu	¹⁶⁶Eu
64	¹⁶¹Gd	¹⁶⁶Gd
65	¹⁶²Tb	¹⁶⁶Tb
66	¹⁶³Dy	¹⁶⁶Dy
67	¹⁶⁴Ho	¹⁶⁶Ho
68	¹⁶⁵Er	¹⁶⁶Er
69	¹⁶⁶Tm	¹⁶⁶Tm
70	¹⁶⁷Yb	¹⁶⁶Yb
71	¹⁶⁸Lu	¹⁶⁶Lu
72	¹⁶⁹Hf	¹⁶⁶Hf
73	¹⁷⁰Ta	¹⁶⁶Ta
74	¹⁷¹W	¹⁶⁶W
75	¹⁷²Re	¹⁶⁶Re
76	¹⁷³Os	¹⁶⁶Os
77	¹⁷⁴Ir	¹⁶⁶Ir
78	¹⁷⁵Pt	¹⁶⁶Pt
79	¹⁷⁶Au
80	¹⁷⁷Hg
81	¹⁷⁸Tl
82	¹⁷⁹Pb