Radon-213

Properties and data of the isotope ²¹³Rn.

Contents

Radon-213 is a radioisotope of the chemical element radon, which has 127 neutrons in its atomic nucleus in addition to the element-specific 86 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 213. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ²¹³Rn is exclusively for academic purposes and experimental research.

In 1967 a research report presented the first description of the short-lived isotope radon-213. In the experiments described therein, 78-MeV carbon-12 ions from a cyclotron struck a lead target, producing radium-isotopes in xn reactions. Subsequent α decay of the nuclide radium-217 finally yielded radon-213, and its presence was unambiguously confirmed from the α-particle energies measured with a silicon surface-barrier detector [H. Rotter et al.: The new isotope Ac²¹⁶, Sov. J. Nucl. Phys. 4, 178, (1967)].

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

General data

Name of the isotope:Radon-213; Rn-213Symbol:²¹³Rn or 21386RnMass number A:213 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:127Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4767441860465 (= neutron-proton ratio)Neutron excess (N-Z):41Isotopic mass:212.993885(4) u (atomic weight of Radon-213)Nuclide mass:212.9467128 u (calculated nuclear mass without electrons)Mass excess:-5.69609 MeVMass defect:1.779512084 u (per nucleus)Nuclear binding energy:1657.60482917 MeV (per nucleus)
7.7821823 MeV (average binding energy per nucleon)Separation energy:S_N = 5.108(4) MeV (first neutron)
S_P = 4.357(4) MeV (first proton)Half-life:19.4(2) msDecay constant λ:35.729236111337 s^-1Specific activity α:1.014936286228 × 10⁺²³ Bq g^-1
2743071043860.5 Ci g^-1Spin and parity:
(nuclear angular momentum)(9/2+)Year of discovery:1967

Radioactive Decay

Half-life T_½ = 19.4(2) ms respectively 1.94 × 10^-2 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁰⁹Po	100 %	8.2452(29) MeV

Parent Nuclides

Direct parent isotopes are: ²¹⁷Ra, ²¹³Fr.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 127) and isobaric (same nucleon number A = 213) with Radon-213. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 127	Isobar A = 213
76	²⁰³Os
77	²⁰⁴Ir
78	²⁰⁵Pt
79	²⁰⁶Au
80	²⁰⁷Hg	²¹³Hg
81	²⁰⁸Tl	²¹³Tl
82	²⁰⁹Pb	²¹³Pb
83	²¹⁰Bi	²¹³Bi
84	²¹¹Po	²¹³Po
85	²¹²At	²¹³At
86	²¹³Rn	²¹³Rn
87	²¹⁴Fr	²¹³Fr
88	²¹⁵Ra	²¹³Ra
89	²¹⁶Ac	²¹³Ac
90	²¹⁷Th	²¹³Th
91	²¹⁸Pa	²¹³Pa
92	²¹⁹U
93	²²⁰Np