Lead-179

Properties and data of the isotope ¹⁷⁹Pb.

Contents

Lead-179 is a radioisotope of the chemical element lead, which has 97 neutrons in its atomic nucleus in addition to the element-specific 82 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 179. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ¹⁷⁹Pb is exclusively for academic purposes and experimental research.

The radioactive nuclide was first produced and identified, according to a 2010 report, by a fusion reaction during the irradiation of a samarium-144 template with calcium-40 ions [1]:

¹⁴⁴Sm(⁴⁰Ca,5n)¹⁷⁹Pb.

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

General data

Name of the isotope:Lead-179; Pb-179Symbol:¹⁷⁹Pb or 17982PbMass number A:179 (= number of nucleons)Atomic number Z:82 (= number of protons)Neutrons N:97Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.1829268292683 (= neutron-proton ratio)Neutron excess (N-Z):15Isotopic mass:179.00220(9) u (atomic weight of Lead-179)Nuclide mass:178.9572216 u (calculated nuclear mass without electrons)Mass excess:2.04929 MeVMass defect:1.479949476 u (per nucleus)Nuclear binding energy:1378.5640572 MeV (per nucleus)
7.70147518 MeV (average binding energy per nucleon)Separation energy:S_N = 9.593(84) MeV (first neutron)
S_P = 0.624(13) MeV (first proton)Half-life:2.7(2) msDecay constant λ:256.72117798516 s^-1Specific activity α:8.636933494723 × 10⁺²³ Bq g^-1
23343063499254 Ci g^-1Spin and parity:
(nuclear angular momentum)(9/2-)Year of discovery:2010

Radioactive Decay

Half-life T_½ = 2.7(2) ms respectively 2.7 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁷⁵Hg	100 %	7.596(5) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 97) and isobaric (same nucleon number A = 179) with Lead-179. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 97	Isobar A = 179
56	¹⁵³Ba
57	¹⁵⁴La
58	¹⁵⁵Ce
59	¹⁵⁶Pr
60	¹⁵⁷Nd
61	¹⁵⁸Pm
62	¹⁵⁹Sm
63	¹⁶⁰Eu
64	¹⁶¹Gd
65	¹⁶²Tb
66	¹⁶³Dy
67	¹⁶⁴Ho
68	¹⁶⁵Er
69	¹⁶⁶Tm	¹⁷⁹Tm
70	¹⁶⁷Yb	¹⁷⁹Yb
71	¹⁶⁸Lu	¹⁷⁹Lu
72	¹⁶⁹Hf	¹⁷⁹Hf
73	¹⁷⁰Ta	¹⁷⁹Ta
74	¹⁷¹W	¹⁷⁹W
75	¹⁷²Re	¹⁷⁹Re
76	¹⁷³Os	¹⁷⁹Os
77	¹⁷⁴Ir	¹⁷⁹Ir
78	¹⁷⁵Pt	¹⁷⁹Pt
79	¹⁷⁶Au	¹⁷⁹Au
80	¹⁷⁷Hg	¹⁷⁹Hg
81	¹⁷⁸Tl	¹⁷⁹Tl
82	¹⁷⁹Pb	¹⁷⁹Pb

External data and identifiers

Adopted Levels, Gammas:NuDat 179Pb

Literature and References

[1] - A. N. Andreyev et al.:
The new isotope ¹⁷⁹Pb and α-decay properties of ¹⁷⁹Tl^m.
In: Journal of Physics G: Nuclear and Particle Physics, 37, 035102, (2010), DOI 10.1088/0954-3899/37/3/035102.