Lead-217

Properties and data of the isotope ²¹⁷Pb.

Contents

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

General data

Name of the isotope:Lead-217; Pb-217Symbol:²¹⁷Pb or 21782PbMass number A:217 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:135Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.6463414634146 (= neutron-proton ratio)Neutron excess (N-Z):53Isotopic mass:217.01314(32) u (atomic weight of Lead-217)Nuclide mass:216.9681616 u (calculated nuclear mass without electrons)Mass excess:12.23983 MeVMass defect:1.798276284 u (per nucleus)Nuclear binding energy:1675.08356889 MeV (per nucleus)
7.71927912 MeV (average binding energy per nucleon)Separation energy:S_N = 3.31(36) MeV (first neutron)
S_P = 9.77(42) MeV (first proton)Half-life:19.9(53) sDecay constant λ:0.034831516611053 s^-1Specific activity α:9.666373244100 × 10⁺¹⁹ Bq g^-1
2612533309.2164 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2009

Radioactive Decay

Half-life T_½ = 19.9(53) s respectively 1.99 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²¹⁷Bi	100 %	3.51(30) 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 = 217) with Lead-217. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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