Polonium-190

Properties and data of the isotope ¹⁹⁰Po.

Contents

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

General data

Name of the isotope:Polonium-190; Po-190Symbol:¹⁹⁰Po or 19084PoMass number A:190 (= number of nucleons)Atomic number Z:84 (= number of protons)Neutrons N:106Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.2619047619048 (= neutron-proton ratio)Neutron excess (N-Z):22Isotopic mass:189.995101(14) u (atomic weight of Polonium-190)Nuclide mass:189.9490257 u (calculated nuclear mass without electrons)Mass excess:-4.56339 MeVMass defect:1.580682784 u (per nucleus)Nuclear binding energy:1472.3965292 MeV (per nucleus)
7.74945542 MeV (average binding energy per nucleon)Separation energy:S_N = 11.213(26) MeV (first neutron)
S_P = 1.788(25) MeV (first proton)Half-life:2.46(5) msDecay constant λ:281.76714656908 s^-1Specific activity α:8.977997070589 × 10⁺²³ Bq g^-1
24264856947540 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1996

Radioactive Decay

Half-life T_½ = 2.46(5) ms respectively 2.46 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁸⁶Pb	100 %	7.693(7) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 106) and isobaric (same nucleon number A = 190) with Polonium-190. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 106	Isobar A = 190
64	¹⁷⁰Gd
65	¹⁷¹Tb
66	¹⁷²Dy
67	¹⁷³Ho
68	¹⁷⁴Er
69	¹⁷⁵Tm
70	¹⁷⁶Yb
71	¹⁷⁷Lu
72	¹⁷⁸Hf	¹⁹⁰Hf
73	¹⁷⁹Ta	¹⁹⁰Ta
74	¹⁸⁰W	¹⁹⁰W
75	¹⁸¹Re	¹⁹⁰Re
76	¹⁸²Os	¹⁹⁰Os
77	¹⁸³Ir	¹⁹⁰Ir
78	¹⁸⁴Pt	¹⁹⁰Pt
79	¹⁸⁵Au	¹⁹⁰Au
80	¹⁸⁶Hg	¹⁹⁰Hg
81	¹⁸⁷Tl	¹⁹⁰Tl
82	¹⁸⁸Pb	¹⁹⁰Pb
83	¹⁸⁹Bi	¹⁹⁰Bi
84	¹⁹⁰Po	¹⁹⁰Po
85	¹⁹¹At	¹⁹⁰At