Radon-197

Properties and data of the isotope ¹⁹⁷Rn.

Contents

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

General data

Name of the isotope:Radon-197; Rn-197Symbol:¹⁹⁷Rn or 19786RnMass number A:197 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:111Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.2906976744186 (= neutron-proton ratio)Neutron excess (N-Z):25Isotopic mass:197.001621(17) u (atomic weight of Radon-197)Nuclide mass:196.9544488 u (calculated nuclear mass without electrons)Mass excess:1.50995 MeVMass defect:1.633137428 u (per nucleus)Nuclear binding energy:1521.25771536 MeV (per nucleus)
7.72212038 MeV (average binding energy per nucleon)Separation energy:S_N = 8.532(22) MeV (first neutron)
S_P = 1.86(3) MeV (first proton)Half-life:ca. 65 msDecay constant λ:10.663802777845 s^-1Specific activity α:3.259843778211 × 10⁺²² Bq g^-1
881038858976.11 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2-)Year of discovery:1995

Radioactive Decay

Half-life T_½ = ca. 65 ms respectively 6.5 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁹³Po	~ 100 %	7.411(7) MeV

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
^197mRn	(200 keV)	ca. 19 ms	(13/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 111) and isobaric (same nucleon number A = 197) with Radon-197. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 111	Isobar A = 197
70	¹⁸¹Yb
71	¹⁸²Lu
72	¹⁸³Hf
73	¹⁸⁴Ta
74	¹⁸⁵W	¹⁹⁷W
75	¹⁸⁶Re	¹⁹⁷Re
76	¹⁸⁷Os	¹⁹⁷Os
77	¹⁸⁸Ir	¹⁹⁷Ir
78	¹⁸⁹Pt	¹⁹⁷Pt
79	¹⁹⁰Au	¹⁹⁷Au
80	¹⁹¹Hg	¹⁹⁷Hg
81	¹⁹²Tl	¹⁹⁷Tl
82	¹⁹³Pb	¹⁹⁷Pb
83	¹⁹⁴Bi	¹⁹⁷Bi
84	¹⁹⁵Po	¹⁹⁷Po
85	¹⁹⁶At	¹⁹⁷At
86	¹⁹⁷Rn	¹⁹⁷Rn