Tungsten-189

Properties and data of the isotope ¹⁸⁹W.

Contents

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

General data

Name of the isotope:Tungsten-189; W-189Symbol:¹⁸⁹W or 18974WMass number A:189 (= number of nucleons)Atomic number Z:74 (= number of protons)Neutrons N:115Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.5540540540541 (= neutron-proton ratio)Neutron excess (N-Z):41Isotopic mass:188.96176(4) u (atomic weight of Tungsten-189)Nuclide mass:188.9211691 u (calculated nuclear mass without electrons)Mass excess:-35.62033 MeVMass defect:1.613757708 u (per nucleus)Nuclear binding energy:1503.20562246 MeV (per nucleus)
7.9534689 MeV (average binding energy per nucleon)Separation energy:S_N = 5.02(4) MeV (first neutron)
S_P = 9.29(7) MeV (first proton)Half-life:11.6(2) minDecay constant λ:0.00099418700596665 s^-1Specific activity α:3.184645846303 × 10⁺¹⁸ Bq g^-1
86071509.359543 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2-)Year of discovery:1963

Radioactive Decay

Half-life T_½ = 11.6(2) min (minutes) respectively 6.972 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁸⁹Re	100 %	2.36(4) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 115) and isobaric (same nucleon number A = 189) with Tungsten-189. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 115	Isobar A = 189
70	¹⁸⁵Yb
71	¹⁸⁶Lu
72	¹⁸⁷Hf	¹⁸⁹Hf
73	¹⁸⁸Ta	¹⁸⁹Ta
74	¹⁸⁹W	¹⁸⁹W
75	¹⁹⁰Re	¹⁸⁹Re
76	¹⁹¹Os	¹⁸⁹Os
77	¹⁹²Ir	¹⁸⁹Ir
78	¹⁹³Pt	¹⁸⁹Pt
79	¹⁹⁴Au	¹⁸⁹Au
80	¹⁹⁵Hg	¹⁸⁹Hg
81	¹⁹⁶Tl	¹⁸⁹Tl
82	¹⁹⁷Pb	¹⁸⁹Pb
83	¹⁹⁸Bi	¹⁸⁹Bi
84	¹⁹⁹Po	¹⁸⁹Po
85	²⁰⁰At	¹⁸⁹At
86	²⁰¹Rn
87	²⁰²Fr
88	²⁰³Ra
89	²⁰⁴Ac