Bismuth-204

Properties and data of the isotope ²⁰⁴Bi.

Contents

General data

Name of the isotope:Bismuth-204; Bi-204Symbol:²⁰⁴Bi or 20483BiMass number A:204 (= number of nucleons)Atomic number Z:83 (= number of protons)Neutrons N:121Isotopic mass:203.977836(10) u (atomic weight of Bismuth-204)Nuclide mass:203.9323091 u (calculated nuclear mass without electrons)Mass excess:-20.64563 MeVMass defect:1.720096492 u (per nucleus)Nuclear binding energy:1602.25956172 MeV (per nucleus)
7.85421354 MeV (average binding energy per nucleon)Separation energy:S_N = 7.192(16) MeV (first neutron)
S_P = 3.148(11) MeV (first proton)Half-life:11.22(10) hDecay constant λ:1.71605065498 × 10^-5 s^-1Specific activity α:5.090787569991 × 10⁺¹⁶ Bq g^-1
1375888.5324301 Ci g^-1Spin and parity:
(nuclear angular momentum)6+Magnetic dipole moment:μ(μ_N) = + 4.322(15)Quadrupole moment Q:- 0.49(15) barn (100 fm²)Nuclear g-factor:g_l = 0.72033333333333Charge radius:5.4934(910) femtometer fmYear of discovery:1947

Radioactive Decay

Half-life T_½ = 11.22(10) h (hours) respectively 4.0392 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	²⁰⁴Pb	100 %	4.464(9) MeV

Parent Nuclides

Direct parent isotopes are: ²⁰⁸At, ²⁰⁴Po.

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
^204m1Bi	805.5(3) keV	13.0(1) ms	10-
^204m2Bi	2833.4(11) keV	1.07(3) ms	17+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 121) and isobaric (same nucleon number A = 204) with Bismuth-204. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 121	Isobar A = 204
73	¹⁹⁴Ta
74	¹⁹⁵W
75	¹⁹⁶Re
76	¹⁹⁷Os
77	¹⁹⁸Ir	²⁰⁴Ir
78	¹⁹⁹Pt	²⁰⁴Pt
79	²⁰⁰Au	²⁰⁴Au
80	²⁰¹Hg	²⁰⁴Hg
81	²⁰²Tl	²⁰⁴Tl
82	²⁰³Pb	²⁰⁴Pb
83	²⁰⁴Bi	²⁰⁴Bi
84	²⁰⁵Po	²⁰⁴Po
85	²⁰⁶At	²⁰⁴At
86	²⁰⁷Rn	²⁰⁴Rn
87	²⁰⁸Fr	²⁰⁴Fr
88	²⁰⁹Ra	²⁰⁴Ra
89	²¹⁰Ac	²⁰⁴Ac
90	²¹¹Th
91	²¹²Pa