Radon-202

Properties and data of the isotope ²⁰²Rn.

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-202; Rn-202Symbol:²⁰²Rn or 20286RnMass number A:202 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:116Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3488372093023 (= neutron-proton ratio)Neutron excess (N-Z):30Isotopic mass:20.1993264(19) u (atomic weight of Radon-202)Nuclide mass:20.1521542 u (calculated nuclear mass without electrons)Mass excess:-169346.23665 MeVMass defect:183.478756608 u (per nucleus)Nuclear binding energy:170909.36090781 MeV (per nucleus)
846.08594509 MeV (average binding energy per nucleon)Separation energy:S_N = 10.27(5) MeV (first neutron)
S_P = 2.774(19) MeV (first proton)Half-life:9.7(1) sDecay constant λ:0.071458472222675 s^-1Specific activity α:2.151664926804 × 10⁺²¹ Bq g^-1
58153106129.841 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1967

Radioactive Decay

Half-life T_½ = 9.7(1) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁹⁸Po	78(8) %	6.7738(18) MeV
EC/β⁺	²⁰²At	22(8) %	4.32(3) MeV

Parent Nuclides

Direct parent isotope is: ²⁰⁶Ra.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 116) and isobaric (same nucleon number A = 202) with Radon-202. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 116	Isobar A = 202
71	¹⁸⁷Lu
72	¹⁸⁸Hf
73	¹⁸⁹Ta
74	¹⁹⁰W
75	¹⁹¹Re
76	¹⁹²Os	²⁰²Os
77	¹⁹³Ir	²⁰²Ir
78	¹⁹⁴Pt	²⁰²Pt
79	¹⁹⁵Au	²⁰²Au
80	¹⁹⁶Hg	²⁰²Hg
81	¹⁹⁷Tl	²⁰²Tl
82	¹⁹⁸Pb	²⁰²Pb
83	¹⁹⁹Bi	²⁰²Bi
84	²⁰⁰Po	²⁰²Po
85	²⁰¹At	²⁰²At
86	²⁰²Rn	²⁰²Rn
87	²⁰³Fr	²⁰²Fr
88	²⁰⁴Ra	²⁰²Ra
89	²⁰⁵Ac