Thallium-196m

Properties and data of the isotope ^196mTl.

Contents

See also: List of individual Thallium isotopes (and general data sources).

General data

Name of the isotope:Thallium-196m; Tl-196mSymbol:^196mTl or 196m81TlMass number A:196 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:115Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.4197530864198 (= neutron-proton ratio)Neutron excess (N-Z):34Excitation energy:394.2(5) keVIsotopic mass:195.970481(13) u (atomic weight of Thallium-196m)Nuclide mass:195.926051 u (calculated nuclear mass without electrons)Mass excess:-27.49677 MeVMass defect:1.659811932 u (per nucleus)Nuclear binding energy:1546.10485579 MeV (per nucleus)
7.88829008 MeV (average binding energy per nucleon)Half-life:1.41(2) hDecay constant λ:0.00013655381807722 s^-1Specific activity α:4.217160653452 × 10⁺¹⁷ Bq g^-1
11397731.495816 Ci g^-1Spin and parity:
(nuclear angular momentum)(7+)

Radioactive Decay

Half-life T_½ = 1.41(2) h (hours) respectively 5.076 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁹⁶Hg	96.2(4) %
Iso	¹⁹⁶Tl	3.8(4) %

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
¹⁹⁶Tl		1.84(3) h	2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 115) and isobaric (same nucleon number A = 196) with Thallium-196m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 115	Isobar A = 196
70	¹⁸⁵Yb
71	¹⁸⁶Lu
72	¹⁸⁷Hf
73	¹⁸⁸Ta
74	¹⁸⁹W	¹⁹⁶W
75	¹⁹⁰Re	¹⁹⁶Re
76	¹⁹¹Os	¹⁹⁶Os
77	¹⁹²Ir	¹⁹⁶Ir
78	¹⁹³Pt	¹⁹⁶Pt
79	¹⁹⁴Au	¹⁹⁶Au
80	¹⁹⁵Hg	¹⁹⁶Hg
81	¹⁹⁶Tl	¹⁹⁶Tl
82	¹⁹⁷Pb	¹⁹⁶Pb
83	¹⁹⁸Bi	¹⁹⁶Bi
84	¹⁹⁹Po	¹⁹⁶Po
85	²⁰⁰At	¹⁹⁶At
86	²⁰¹Rn	¹⁹⁶Rn
87	²⁰²Fr
88	²⁰³Ra
89	²⁰⁴Ac