Thallium-184

Properties and data of the isotope ¹⁸⁴Tl.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Thallium-184; Tl-184Symbol:¹⁸⁴Tl or 18481TlMass number A:184 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:103Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.2716049382716 (= neutron-proton ratio)Neutron excess (N-Z):22Isotopic mass:183.981875(11) u (atomic weight of Thallium-184)Nuclide mass:183.937445 u (calculated nuclear mass without electrons)Mass excess:-16.88333 MeVMass defect:1.54443894 u (per nucleus)Nuclear binding energy:1438.63560598 MeV (per nucleus)
7.81867177 MeV (average binding energy per nucleon)Separation energy:S_N = 8.367(14) MeV (first neutron)
S_P = 0.368(12) MeV (first proton)Half-life:10.1(5) sDecay constant λ:0.068628433718806 s^-1Specific activity α:2.258415818860 × 10⁺²⁰ Bq g^-1
6103826537.4611 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1976

Radioactive Decay

Half-life T_½ = 10.1(5) s respectively 1.01 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁸⁰Au	2.1(7) %	6.317(9) MeV
EC/β⁺	¹⁸⁴Hg	97.9(7) %	9.466(14) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸⁸Bi.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 103) and isobaric (same nucleon number A = 184) with Thallium-184. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 103	Isobar A = 184
60	¹⁶³Nd
62	¹⁶⁵Sm
63	¹⁶⁶Eu
64	¹⁶⁷Gd
65	¹⁶⁸Tb
66	¹⁶⁹Dy
67	¹⁷⁰Ho
68	¹⁷¹Er
69	¹⁷²Tm
70	¹⁷³Yb	¹⁸⁴Yb
71	¹⁷⁴Lu	¹⁸⁴Lu
72	¹⁷⁵Hf	¹⁸⁴Hf
73	¹⁷⁶Ta	¹⁸⁴Ta
74	¹⁷⁷W	¹⁸⁴W
75	¹⁷⁸Re	¹⁸⁴Re
76	¹⁷⁹Os	¹⁸⁴Os
77	¹⁸⁰Ir	¹⁸⁴Ir
78	¹⁸¹Pt	¹⁸⁴Pt
79	¹⁸²Au	¹⁸⁴Au
80	¹⁸³Hg	¹⁸⁴Hg
81	¹⁸⁴Tl	¹⁸⁴Tl
82	¹⁸⁵Pb	¹⁸⁴Pb
83	¹⁸⁶Bi	¹⁸⁴Bi
84	¹⁸⁷Po
85	¹⁸⁸At