Radon-212m1

Properties and data of the isotope ^212m1Rn.

Contents

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

General data

Name of the isotope:Radon-212m1; Rn-212m1Symbol:^212m1Rn or 212m186RnMass number A:212 (= number of nucleons)Atomic number Z:86 (= number of protons)Neutrons N:126Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.4651162790698 (= neutron-proton ratio)Neutron excess (N-Z):40Excitation energy:1639.68(15) keVIsotopic mass:211.990704(3) u (atomic weight of Radon-212m1)Nuclide mass:211.9435318 u (calculated nuclear mass without electrons)Mass excess:-8.65917 MeVMass defect:1.774028168 u (per nucleus)Nuclear binding energy:1652.49659432 MeV (per nucleus)
7.79479526 MeV (average binding energy per nucleon)Half-life:118(14) nsDecay constant λ:5874128.6488131 s^-1Specific activity α:1.676532234717 × 10⁺²⁸ Bq g^-1
4.531168201939 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)6+Magnetic dipole moment:μ(μ_N) = 5.45(5)Nuclear g-factor:g_l = 0.90833333333333Year of discovery:1971

Radioactive Decay

Half-life T_½ = 118(14) ns respectively 1.18 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²¹²Rn	100 %

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
²¹²Rn		23.9(12) ms	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 126) and isobaric (same nucleon number A = 212) with Radon-212m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 126	Isobar A = 212
76	²⁰²Os
77	²⁰³Ir
78	²⁰⁴Pt
79	²⁰⁵Au
80	²⁰⁶Hg	²¹²Hg
81	²⁰⁷Tl	²¹²Tl
82	²⁰⁸Pb	²¹²Pb
83	²⁰⁹Bi	²¹²Bi
84	²¹⁰Po	²¹²Po
85	²¹¹At	²¹²At
86	²¹²Rn	²¹²Rn
87	²¹³Fr	²¹²Fr
88	²¹⁴Ra	²¹²Ra
89	²¹⁵Ac	²¹²Ac
90	²¹⁶Th	²¹²Th
91	²¹⁷Pa	²¹²Pa
92	²¹⁸U
93	²¹⁹Np