Radon-200m

Properties and data of the isotope ^200mRn.

Contents

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

General data

Name of the isotope:Radon-200m; Rn-200mSymbol:^200mRn or 200m86RnMass number A:200 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:114Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.3255813953488 (= neutron-proton ratio)Neutron excess (N-Z):28Excitation energy:2300.5(5)+xIsotopic mass:199.995701(15) u (atomic weight of Radon-200m)Nuclide mass:199.9485288 u (calculated nuclear mass without electrons)Mass excess:-4.00449 MeVMass defect:1.665052176 u (per nucleus)Nuclear binding energy:1550.98611163 MeV (per nucleus)
7.75493056 MeV (average binding energy per nucleon)Half-life:25 μsDecay constant λ:27725.887222398 s^-1Specific activity α:8.390411975879 × 10⁺²⁵ Bq g^-1
2.267678912399 × 10⁺¹⁵ Ci g^-1Spin and parity:
(nuclear angular momentum)

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
²⁰⁰Rn		ca. 1.03 s	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 114) and isobaric (same nucleon number A = 200) with Radon-200m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 114	Isobar A = 200
70	¹⁸⁴Yb
71	¹⁸⁵Lu
72	¹⁸⁶Hf
73	¹⁸⁷Ta
74	¹⁸⁸W
75	¹⁸⁹Re
76	¹⁹⁰Os	²⁰⁰Os
77	¹⁹¹Ir	²⁰⁰Ir
78	¹⁹²Pt	²⁰⁰Pt
79	¹⁹³Au	²⁰⁰Au
80	¹⁹⁴Hg	²⁰⁰Hg
81	¹⁹⁵Tl	²⁰⁰Tl
82	¹⁹⁶Pb	²⁰⁰Pb
83	¹⁹⁷Bi	²⁰⁰Bi
84	¹⁹⁸Po	²⁰⁰Po
85	¹⁹⁹At	²⁰⁰At
86	²⁰⁰Rn	²⁰⁰Rn
87	²⁰¹Fr	²⁰⁰Fr
88	²⁰²Ra
89	²⁰³Ac