Thallium-190

Properties and data of the isotope ¹⁹⁰Tl.

Content

General data

Name of the isotope:Thallium-190; Tl-190Symbol:¹⁹⁰Tl or 19081TlMass number A:190 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:109Isotopic mass:189.973836(9) u (atomic weight of Thallium-190)
Excitation energy: +x keVNuclide mass:189.929406 u (calculated nuclear mass without electrons)Mass excess:-24.37161 MeVMass defect:1.604467436 u (per nucleus)Nuclear binding energy:1494.55178983 MeV (per nucleus)
7.86606205 MeV (average binding energy per nucleon)Separation energy:S_N = 7.827(12) MeV (first neutron)
S_P = 2.03(3) MeV (first proton)Half-life:2.6(3) minDecay constant λ:0.0044432511574355 s^-1Specific activity α:1.415761076516 × 10⁺¹⁹ Bq g^-1
382638128.78814 Ci g^-1Spin and parity:
(nuclear angular momentum)2(-)Magnetic dipole moment:μ(μ_N) = + 0.254(2)Quadrupole moment Q:- 0.329(9) barn (100 fm²)Nuclear g-factor:g_l = 0.127Charge radius:5.4121(56) femtometer fmYear of discovery:1970

Radioactive Decay

Half-life T_½ = 2.6(3) min (minutes) respectively 1.56 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	¹⁹⁰Hg	100 %	6.999(18) MeV

Parent Nuclides

Direct parent isotopes are: ¹⁹⁴Bi, ¹⁹⁰Pb.

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
^190m1Tl	+y keV	3.7(3) min	7(+)
^190m2Tl	161.9+y keV	0.75(4) ms	(8-)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 109) and isobaric (same nucleon number A = 190) with Thallium-190. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 109	Isobar A = 190
68	¹⁷⁷Er
69	¹⁷⁸Tm
70	¹⁷⁹Yb
71	¹⁸⁰Lu
72	¹⁸¹Hf	¹⁹⁰Hf
73	¹⁸²Ta	¹⁹⁰Ta
74	¹⁸³W	¹⁹⁰W
75	¹⁸⁴Re	¹⁹⁰Re
76	¹⁸⁵Os	¹⁹⁰Os
77	¹⁸⁶Ir	¹⁹⁰Ir
78	¹⁸⁷Pt	¹⁹⁰Pt
79	¹⁸⁸Au	¹⁹⁰Au
80	¹⁸⁹Hg	¹⁹⁰Hg
81	¹⁹⁰Tl	¹⁹⁰Tl
82	¹⁹¹Pb	¹⁹⁰Pb
83	¹⁹²Bi	¹⁹⁰Bi
84	¹⁹³Po	¹⁹⁰Po
85	¹⁹⁴At	¹⁹⁰At
86	¹⁹⁵Rn