Thallium-194m

Properties and data of the isotope ¹⁹⁴Tl.

Content

General data

Name of the isotope:Thallium-194m; Tl-194mSymbol:¹⁹⁴Tl or 19481TlMass number A:194 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:113Isotopic mass:193.971081(15) u (atomic weight of Thallium-194m)
Excitation energy: +x keVNuclide mass:193.926651 u (calculated nuclear mass without electrons)Mass excess:-26.93787 MeVMass defect:1.6418821 u (per nucleus)Nuclear binding energy:1529.40332486 MeV (per nucleus)
7.88352229 MeV (average binding energy per nucleon)Half-life:32.8(2) minDecay constant λ:0.00035220893321135 s^-1Specific activity α:1.098990574055 × 10⁺¹⁸ Bq g^-1
29702447.947443 Ci g^-1Spin and parity:
(nuclear angular momentum)(7+)Magnetic dipole moment:μ(μ_N) = 0.530(8)Quadrupole moment Q:+ 0.607(16) barn (100 fm²)Nuclear g-factor:g_l = 0.075714285714286

Radioactive Decay

Half-life T_½ = 32.8(2) min (minutes) respectively 1.968 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹⁹⁴Hg	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
¹⁹⁴Tl		33.0(5) min	2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 113) and isobaric (same nucleon number A = 194) with Thallium-194m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 113	Isobar A = 194
70	¹⁸³Yb
71	¹⁸⁴Lu
72	¹⁸⁵Hf
73	¹⁸⁶Ta	¹⁹⁴Ta
74	¹⁸⁷W	¹⁹⁴W
75	¹⁸⁸Re	¹⁹⁴Re
76	¹⁸⁹Os	¹⁹⁴Os
77	¹⁹⁰Ir	¹⁹⁴Ir
78	¹⁹¹Pt	¹⁹⁴Pt
79	¹⁹²Au	¹⁹⁴Au
80	¹⁹³Hg	¹⁹⁴Hg
81	¹⁹⁴Tl	¹⁹⁴Tl
82	¹⁹⁵Pb	¹⁹⁴Pb
83	¹⁹⁶Bi	¹⁹⁴Bi
84	¹⁹⁷Po	¹⁹⁴Po
85	¹⁹⁸At	¹⁹⁴At
86	¹⁹⁹Rn	¹⁹⁴Rn
87	²⁰⁰Fr
88	²⁰¹Ra