Polonium-219

Properties and data of the isotope ²¹⁹Po.

Contents

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

General data

Name of the isotope:Polonium-219; Po-219Symbol:²¹⁹Po or 21984PoMass number A:219 (= number of nucleons)Atomic number Z:84 (= number of protons)Neutrons N:135Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.6071428571429 (= neutron-proton ratio)Neutron excess (N-Z):51Isotopic mass:219.013614(17) u (atomic weight of Polonium-219)Nuclide mass:218.9675387 u (calculated nuclear mass without electrons)Mass excess:12.68136 MeVMass defect:1.813452348 u (per nucleus)Nuclear binding energy:1689.21998145 MeV (per nucleus)
7.71333325 MeV (average binding energy per nucleon)Separation energy:S_N = 3.747(16) MeV (first neutron)
S_P = 7.82(3) MeV (first proton)Half-life:620(59) sDecay constant λ:0.0011179793234838 s^-1Specific activity α:3.074259801148 × 10⁺¹⁸ Bq g^-1
83088102.733754 Ci g^-1Spin and parity:
(nuclear angular momentum)(9/2+)Year of discovery:1998

Radioactive Decay

Half-life T_½ = 620(59) s respectively 6.20 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²¹⁹At	71.8(20) %	2.285(16) MeV
α	²¹⁵Pb	28.2(20) %	5.91(5) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 135) and isobaric (same nucleon number A = 219) with Polonium-219. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 135	Isobar A = 219
80	²¹⁵Hg
81	²¹⁶Tl
82	²¹⁷Pb	²¹⁹Pb
83	²¹⁸Bi	²¹⁹Bi
84	²¹⁹Po	²¹⁹Po
85	²²⁰At	²¹⁹At
86	²²¹Rn	²¹⁹Rn
87	²²²Fr	²¹⁹Fr
88	²²³Ra	²¹⁹Ra
89	²²⁴Ac	²¹⁹Ac
90	²²⁵Th	²¹⁹Th
91	²²⁶Pa	²¹⁹Pa
92	²²⁷U	²¹⁹U
93	²²⁸Np	²¹⁹Np
94	²²⁹Pu
95	²³⁰Am