Platinum-181

Properties and data of the isotope ¹⁸¹Pt.

Content

General data

Name of the isotope:Platinum-181; Pt-181Symbol:¹⁸¹Pt or 18178PtMass number A:181 (= number of nucleons)Atomic number Z:78 (= number of protons)Neutrons N:103Isotopic mass:180.963090(15) u (atomic weight of Platinum-181)Nuclide mass:180.9203053 u (calculated nuclear mass without electrons)Mass excess:-34.38144 MeVMass defect:1.539748844 u (per nucleus)Nuclear binding energy:1434.26680969 MeV (per nucleus)
7.92412602 MeV (average binding energy per nucleon)Separation energy:S_N = 8.017(18) MeV (first neutron)
S_P = 3.693(26) MeV (first proton)Half-life:52.0(22) sDecay constant λ:0.013329753472307 s^-1Specific activity α:4.459647391025 × 10⁺¹⁹ Bq g^-1
1205310105.6826 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2-Magnetic dipole moment:μ(μ_N) = + 0.484(21)Nuclear g-factor:g_l = 0.968Charge radius:5.3996(41) femtometer fmYear of discovery:1966

Radioactive Decay

Half-life T_½ = 52.0(22) s respectively 5.20 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁷⁷Os	ca. 0.08 %	5.15(5) MeV
EE/β⁺	¹⁸¹Ir	ca. 99.92 %	5.082(15) %

Parent Nuclides

Direct parent isotopes are: ¹⁸⁵Hg, ¹⁸¹Au.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 103) and isobaric (same nucleon number A = 181) with Platinum-181. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 103	Isobar A = 181
60	¹⁶³Nd
62	¹⁶⁵Sm
63	¹⁶⁶Eu
64	¹⁶⁷Gd
65	¹⁶⁸Tb
66	¹⁶⁹Dy
67	¹⁷⁰Ho
68	¹⁷¹Er
69	¹⁷²Tm
70	¹⁷³Yb	¹⁸¹Yb
71	¹⁷⁴Lu	¹⁸¹Lu
72	¹⁷⁵Hf	¹⁸¹Hf
73	¹⁷⁶Ta	¹⁸¹Ta
74	¹⁷⁷W	¹⁸¹W
75	¹⁷⁸Re	¹⁸¹Re
76	¹⁷⁹Os	¹⁸¹Os
77	¹⁸⁰Ir	¹⁸¹Ir
78	¹⁸¹Pt	¹⁸¹Pt
79	¹⁸²Au	¹⁸¹Au
80	¹⁸³Hg	¹⁸¹Hg
81	¹⁸⁴Tl	¹⁸¹Tl
82	¹⁸⁵Pb	¹⁸¹Pb
83	¹⁸⁶Bi
84	¹⁸⁷Po