Thallium-179m

Properties and data of the isotope ¹⁷⁹Tl.

Content

General data

Name of the isotope:Thallium-179m; Tl-179mSymbol:¹⁷⁹Tl or 17981TlMass number A:179 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:98Isotopic mass:178.99112(4) u (atomic weight of Thallium-179m)
Excitation energy: +x keVNuclide mass:178.94669 u (calculated nuclear mass without electrons)Mass excess:-8.27167 MeVMass defect:1.49186936 u (per nucleus)Nuclear binding energy:1389.66735762 MeV (per nucleus)
7.76350479 MeV (average binding energy per nucleon)Half-life:1.5(3) msDecay constant λ:462.0981203733 s^-1Specific activity α:1.563382006741 × 10⁺²⁴ Bq g^-1
42253567749773 Ci g^-1Spin and parity:
(nuclear angular momentum)(11/2-)

Radioactive Decay

Half-life T_½ = 1.5(3) ms respectively 1.5 × 10^-3 seconds s.

Decay mode	Daughter	Probability
α	¹⁷⁵Au	< 100 %
p	¹⁷⁸Hg	?
EE/β⁺	¹⁸⁰Hg	?
Iso	¹⁷⁹Tl	?

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
¹⁷⁹Tl		0.23(4) s	(1/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 98) and isobaric (same nucleon number A = 179) with Thallium-179m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 98	Isobar A = 179
57	¹⁵⁵La
58	¹⁵⁶Ce
59	¹⁵⁷Pr
60	¹⁵⁸Nd
61	¹⁵⁹Pm
62	¹⁶⁰Sm
63	¹⁶¹Eu
64	¹⁶²Gd
65	¹⁶³Tb
66	¹⁶⁴Dy
67	¹⁶⁵Ho
68	¹⁶⁶Er
69	¹⁶⁷Tm	¹⁷⁹Tm
70	¹⁶⁸Yb	¹⁷⁹Yb
71	¹⁶⁹Lu	¹⁷⁹Lu
72	¹⁷⁰Hf	¹⁷⁹Hf
73	¹⁷¹Ta	¹⁷⁹Ta
74	¹⁷²W	¹⁷⁹W
75	¹⁷³Re	¹⁷⁹Re
76	¹⁷⁴Os	¹⁷⁹Os
77	¹⁷⁵Ir	¹⁷⁹Ir
78	¹⁷⁶Pt	¹⁷⁹Pt
79	¹⁷⁷Au	¹⁷⁹Au
80	¹⁷⁸Hg	¹⁷⁹Hg
81	¹⁷⁹Tl	¹⁷⁹Tl
82	¹⁸⁰Pb	¹⁷⁹Pb