Thallium-204m1

Properties and data of the isotope ^204m1Tl.

Contents

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

General data

Name of the isotope:Thallium-204m1; Tl-204m1Symbol:^204m1Tl or 204m181TlMass number A:204 (= number of nucleons)Atomic number Z:81 (= number of protons)Neutrons N:123Nucleon pairing (Z - N):odd - oddNuclear ratio (N/Z ratio):1.5185185185185 (= neutron-proton ratio)Neutron excess (N-Z):42Excitation energy:1103.9(3) keVIsotopic mass:203.9738633(12) u (atomic weight of Thallium-204m1)Nuclide mass:203.9294333 u (calculated nuclear mass without electrons)Mass excess:-24.34618 MeVMass defect:1.72574896 u (per nucleus)Nuclear binding energy:1607.52480175 MeV (per nucleus)
7.88002354 MeV (average binding energy per nucleon)Half-life:61.7(10) μsDecay constant λ:11234.152035007 s^-1Specific activity α:3.332691921022 × 10⁺²⁵ Bq g^-1
9.007275462223 × 10⁺¹⁴ Ci g^-1Spin and parity:
(nuclear angular momentum)(7)+Magnetic dipole moment:μ(μ_N) = +1.187(6)Nuclear g-factor:g_l = 0.16957142857143

Radioactive Decay

Half-life T_½ = 61.7(10) μs respectively 6.17 × 10^-5 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²⁰⁴Tl	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
²⁰⁴Tl		3.783(12) a	2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 123) and isobaric (same nucleon number A = 204) with Thallium-204m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 123	Isobar A = 204
74	¹⁹⁷W
75	¹⁹⁸Re
76	¹⁹⁹Os
77	²⁰⁰Ir	²⁰⁴Ir
78	²⁰¹Pt	²⁰⁴Pt
79	²⁰²Au	²⁰⁴Au
80	²⁰³Hg	²⁰⁴Hg
81	²⁰⁴Tl	²⁰⁴Tl
82	²⁰⁵Pb	²⁰⁴Pb
83	²⁰⁶Bi	²⁰⁴Bi
84	²⁰⁷Po	²⁰⁴Po
85	²⁰⁸At	²⁰⁴At
86	²⁰⁹Rn	²⁰⁴Rn
87	²¹⁰Fr	²⁰⁴Fr
88	²¹¹Ra	²⁰⁴Ra
89	²¹²Ac	²⁰⁴Ac
90	²¹³Th
91	²¹⁴Pa
92	²¹⁵U