Radon-204

Properties and data of the isotope ²⁰⁴Rn.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Radon-204; Rn-204Symbol:²⁰⁴Rn or 20486RnMass number A:204 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:118Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3720930232558 (= neutron-proton ratio)Neutron excess (N-Z):32Isotopic mass:203.991444(8) u (atomic weight of Radon-204)Nuclide mass:203.9442718 u (calculated nuclear mass without electrons)Mass excess:-7.96986 MeVMass defect:1.70396884 u (per nucleus)Nuclear binding energy:1587.23675065 MeV (per nucleus)
7.78057231 MeV (average binding energy per nucleon)Separation energy:S_N = 9.888(20) MeV (first neutron)
S_P = 3.097(13) MeV (first proton)Half-life:74.5(14) sDecay constant λ:0.0093039890008046 s^-1Specific activity α:2.760095188283 × 10⁺¹⁹ Bq g^-1
745971672.50895 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1967

Radioactive Decay

Half-life T_½ = 74.5(14) s respectively 7.45 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁰⁰Po	72.4(9) %	6.5466(18) MeV
EC/β⁺	²⁰⁴At	27.6(9) %	3.905(23) MeV

Parent Nuclides

Direct parent isotope is: ²⁰⁸Ra.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 118) and isobaric (same nucleon number A = 204) with Radon-204. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 118	Isobar A = 204
72	¹⁹⁰Hf
73	¹⁹¹Ta
74	¹⁹²W
75	¹⁹³Re
76	¹⁹⁴Os
77	¹⁹⁵Ir	²⁰⁴Ir
78	¹⁹⁶Pt	²⁰⁴Pt
79	¹⁹⁷Au	²⁰⁴Au
80	¹⁹⁸Hg	²⁰⁴Hg
81	¹⁹⁹Tl	²⁰⁴Tl
82	²⁰⁰Pb	²⁰⁴Pb
83	²⁰¹Bi	²⁰⁴Bi
84	²⁰²Po	²⁰⁴Po
85	²⁰³At	²⁰⁴At
86	²⁰⁴Rn	²⁰⁴Rn
87	²⁰⁵Fr	²⁰⁴Fr
88	²⁰⁶Ra	²⁰⁴Ra
89	²⁰⁷Ac	²⁰⁴Ac
90	²⁰⁸Th