Polonium-188

Properties and data of the isotope ¹⁸⁸Po.

Contents

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

General data

Name of the isotope:Polonium-188; Po-188Symbol:¹⁸⁸Po or 18884PoMass number A:188 (= number of nucleons)Atomic number Z:84 (= number of protons)Neutrons N:104Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.2380952380952 (= neutron-proton ratio)Neutron excess (N-Z):20Isotopic mass:187.999416(21) u (atomic weight of Polonium-188)Nuclide mass:187.9533407 u (calculated nuclear mass without electrons)Mass excess:-0.54399 MeVMass defect:1.559037952 u (per nucleus)Nuclear binding energy:1452.23449806 MeV (per nucleus)
7.72465159 MeV (average binding energy per nucleon)Separation energy:S_N = 11.44(4) MeV (first neutron)
S_P = 1.45(22) MeV (first proton)Half-life:0.27(3) msDecay constant λ:2567.2117798516 s^-1Specific activity α:8.267439013666 × 10⁺²⁴ Bq g^-1
2.234442976666 × 10⁺¹⁴ Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1999

Radioactive Decay

Half-life T_½ = 0.27(3) ms respectively 2.7 × 10^-4 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁸⁴Pb	~100 %	8.082(15) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 104) and isobaric (same nucleon number A = 188) with Polonium-188. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 104	Isobar A = 188
62	¹⁶⁶Sm
63	¹⁶⁷Eu
64	¹⁶⁸Gd
65	¹⁶⁹Tb
66	¹⁷⁰Dy
67	¹⁷¹Ho
68	¹⁷²Er
69	¹⁷³Tm
70	¹⁷⁴Yb
71	¹⁷⁵Lu	¹⁸⁸Lu
72	¹⁷⁶Hf	¹⁸⁸Hf
73	¹⁷⁷Ta	¹⁸⁸Ta
74	¹⁷⁸W	¹⁸⁸W
75	¹⁷⁹Re	¹⁸⁸Re
76	¹⁸⁰Os	¹⁸⁸Os
77	¹⁸¹Ir	¹⁸⁸Ir
78	¹⁸²Pt	¹⁸⁸Pt
79	¹⁸³Au	¹⁸⁸Au
80	¹⁸⁴Hg	¹⁸⁸Hg
81	¹⁸⁵Tl	¹⁸⁸Tl
82	¹⁸⁶Pb	¹⁸⁸Pb
83	¹⁸⁷Bi	¹⁸⁸Bi
84	¹⁸⁸Po	¹⁸⁸Po
85	¹⁸⁹At	¹⁸⁸At