Polonium-206

Properties and data of the isotope ²⁰⁶Po.

Content

General data

Name of the isotope:Polonium-206; Po-206Symbol:²⁰⁶Po or 20684PoMass number A:206 (= number of nucleons)Atomic number Z:84 (= number of protons)Neutrons N:122Isotopic mass:205.980474(4) u (atomic weight of Polonium-206)Nuclide mass:205.9343987 u (calculated nuclear mass without electrons)Mass excess:-18.18835 MeVMass defect:1.73394844 u (per nucleus)Nuclear binding energy:1615.16256817 MeV (per nucleus)
7.84059499 MeV (average binding energy per nucleon)Separation energy:S_N = 8.739(11) MeV (first neutron)
S_P = 4.413(6) MeV (first proton)Half-life:8.8(1) dDecay constant λ:9.116519104586 × 10^-7 s^-1Specific activity α:2.678095717079 × 10⁺¹⁵ Bq g^-1
72380.965326468 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:5.5480(177) femtometer fmYear of discovery:1947

Radioactive Decay

Half-life T_½ = 8.8(1) d respectively 7.6032 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁰²Pb	5.45(5) %	5.3270(13) MeV
EE/β⁺	²⁰⁶Bi	94.55(5) %	1.840(9) MeV

Parent Nuclides

Direct parent isotopes are: ²¹⁰Rn, ²⁰⁶At.

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
^206m1Po	1585.90(11) keV	232(4) ns	8+
^206m2Po	2.262.09(12) keV	1.05(6) μs	9-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 122) and isobaric (same nucleon number A = 206) with Polonium-206. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 122	Isobar A = 206
74	¹⁹⁶W
75	¹⁹⁷Re
76	¹⁹⁸Os
77	¹⁹⁹Ir
78	²⁰⁰Pt	²⁰⁶Pt
79	²⁰¹Au	²⁰⁶Au
80	²⁰²Hg	²⁰⁶Hg
81	²⁰³Tl	²⁰⁶Tl
82	²⁰⁴Pb	²⁰⁶Pb
83	²⁰⁵Bi	²⁰⁶Bi
84	²⁰⁶Po	²⁰⁶Po
85	²⁰⁷At	²⁰⁶At
86	²⁰⁸Rn	²⁰⁶Rn
87	²⁰⁹Fr	²⁰⁶Fr
88	²¹⁰Ra	²⁰⁶Ra
89	²¹¹Ac	²⁰⁶Ac
90	²¹²Th
91	²¹³Pa
92	²¹⁴U