Radon-226

Properties and data of the isotope ²²⁶Rn.

Content

General data

Name of the isotope:Radon-226; Rn-226Symbol:²²⁶Rn or 22686RnMass number A:226 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:140Isotopic mass:226.030861(11) u (atomic weight of Radon-226)Nuclide mass:225.9836888 u (calculated nuclear mass without electrons)Mass excess:28.74684 MeVMass defect:1.855179992 u (per nucleus)Nuclear binding energy:1728.08903147 MeV (per nucleus)
7.64641164 MeV (average binding energy per nucleon)Separation energy:S_N = 5.858(15) MeV (first neutron)
S_P = 8.94(30) MeV (first proton)Half-life:7.4(1) minDecay constant λ:0.0015611422985584 s^-1Specific activity α:4.159919833771 × 10⁺¹⁸ Bq g^-1
112430265.77762 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1969

Radioactive Decay

Half-life T_½ = 7.4(1) min (minutes) respectively 4.44 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²²⁶Fr	100 %	1.227(12) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 140) and isobaric (same nucleon number A = 226) with Radon-226. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 140	Isobar A = 226
83	²²³Bi
84	²²⁴Po	²²⁶Po
85	²²⁵At	²²⁶At
86	²²⁶Rn	²²⁶Rn
87	²²⁷Fr	²²⁶Fr
88	²²⁸Ra	²²⁶Ra
89	²²⁹Ac	²²⁶Ac
90	²³⁰Th	²²⁶Th
91	²³¹Pa	²²⁶Pa
92	²³²U	²²⁶U
93	²³³Np	²²⁶Np
94	²³⁴Pu
95	²³⁵Am
96	²³⁶Cm
97	²³⁷Bk
98	²³⁸Cf