Radon-207

Properties and data of the isotope ²⁰⁷Rn.

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-207; Rn-207Symbol:²⁰⁷Rn or 20786RnMass number A:207 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:121Isotopic mass:206.990730(9) u (atomic weight of Radon-207)Nuclide mass:206.9435578 u (calculated nuclear mass without electrons)Mass excess:-8.63495 MeVMass defect:1.730677588 u (per nucleus)Nuclear binding energy:1612.11578916 MeV (per nucleus)
7.78799898 MeV (average binding energy per nucleon)Separation energy:S_N = 7.573(12) MeV (first neutron)
S_P = 3.494(17) MeV (first proton)Half-life:9.25(17) minDecay constant λ:0.0012489138388467 s^-1Specific activity α:3.651036436630 × 10⁺¹⁸ Bq g^-1
98676660.449481 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2-Magnetic dipole moment:μ(μ_N) = + 0.816(9)Quadrupole moment Q:0.220(22) barn (100 fm²)Nuclear g-factor:g_l = 0.3264Charge radius:5.5652(178) femtometer fmYear of discovery:1954

Radioactive Decay

Half-life T_½ = 9.25(17) min (minutes) respectively 5.55 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁰³Po	21(3) %	6.2512(16) MeV
EC/β⁺	²⁰⁷At	79(3) %	4.593(15) MeV

Parent Nuclides

Direct parent isotopes are: ²¹¹Ra, ²⁰⁷Fr.

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
^207mRn	899.1(10) keV	184.5(9) μs	13/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 121) and isobaric (same nucleon number A = 207) with Radon-207. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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