Platinum-189

Properties and data of the isotope ¹⁸⁹Pt.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Platinum-189; Pt-189Symbol:¹⁸⁹Pt or 18978PtMass number A:189 (= number of nucleons)Atomic number Z:78 (= number of protons)Neutrons N:111Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.4230769230769 (= neutron-proton ratio)Neutron excess (N-Z):33Isotopic mass:188.960849(11) u (atomic weight of Platinum-189)Nuclide mass:188.9180643 u (calculated nuclear mass without electrons)Mass excess:-36.46892 MeVMass defect:1.611309172 u (per nucleus)Nuclear binding energy:1500.92482586 MeV (per nucleus)
7.9414012 MeV (average binding energy per nucleon)Separation energy:S_N = 6.720(11) MeV (first neutron)
S_P = 5.413(14) MeV (first proton)Half-life:10.87(12) hDecay constant λ:1.771305275886 × 10^-5 s^-1Specific activity α:5.673962700711 × 10⁺¹⁶ Bq g^-1
1533503.4326248 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2-Magnetic dipole moment:μ(μ_N) = - 0.421(5)Quadrupole moment Q:- 1.03(5) barn (100 fm²)Nuclear g-factor:g_l = -0.28066666666667Charge radius:5.4060(35) femtometer fmYear of discovery:1955

Radioactive Decay

Half-life T_½ = 10.87(12) h (hours) respectively 3.9132 × 10⁴ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁸⁹Ir	100 %	1.980(16) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸⁹Au.

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^189m1Pt	172.79(6) keV	464(25) ns	9/2-
^189m2Pt	191.4(2) keV	143(5) μs	(13/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 111) and isobaric (same nucleon number A = 189) with Platinum-189. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 111	Isobar A = 189
70	¹⁸¹Yb
71	¹⁸²Lu
72	¹⁸³Hf	¹⁸⁹Hf
73	¹⁸⁴Ta	¹⁸⁹Ta
74	¹⁸⁵W	¹⁸⁹W
75	¹⁸⁶Re	¹⁸⁹Re
76	¹⁸⁷Os	¹⁸⁹Os
77	¹⁸⁸Ir	¹⁸⁹Ir
78	¹⁸⁹Pt	¹⁸⁹Pt
79	¹⁹⁰Au	¹⁸⁹Au
80	¹⁹¹Hg	¹⁸⁹Hg
81	¹⁹²Tl	¹⁸⁹Tl
82	¹⁹³Pb	¹⁸⁹Pb
83	¹⁹⁴Bi	¹⁸⁹Bi
84	¹⁹⁵Po	¹⁸⁹Po
85	¹⁹⁶At	¹⁸⁹At
86	¹⁹⁷Rn