Tantalum-186

Properties and data of the isotope ¹⁸⁶Ta.

Contents

General data

Name of the isotope:Tantalum-186; Ta-186Symbol:¹⁸⁶Ta or 18673TaMass number A:186 (= number of nucleons)Atomic number Z:73 (= number of protons)Neutrons N:113Isotopic mass:185.95855(6) u (atomic weight of Tantalum-186)Nuclide mass:185.9185076 u (calculated nuclear mass without electrons)Mass excess:-38.61043 MeVMass defect:1.591812844 u (per nucleus)Nuclear binding energy:1482.76411331 MeV (per nucleus)
7.97185007 MeV (average binding energy per nucleon)Separation energy:S_N = 5.28(6) MeV (first neutron)
S_P = 7.58(9) MeV (first proton)Half-life:10.5(3) minDecay constant λ:0.0011002336199364 s^-1Specific activity α:3.581492885456 × 10⁺¹⁸ Bq g^-1
96797105.012349 Ci g^-1Spin and parity:
(nuclear angular momentum)(2-.3-)Year of discovery:1955

Radioactive Decay

Half-life T_½ = 10.5(3) min (minutes) respectively 6.30 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	¹⁸⁶W	100 %	3.90(6) MeV

Parent Nuclides

Direct parent isotope is: ¹⁸⁶Hf.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 113) and isobaric (same nucleon number A = 186) with Tantalum-186. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 113	Isobar A = 186
70	¹⁸³Yb
71	¹⁸⁴Lu	¹⁸⁶Lu
72	¹⁸⁵Hf	¹⁸⁶Hf
73	¹⁸⁶Ta	¹⁸⁶Ta
74	¹⁸⁷W	¹⁸⁶W
75	¹⁸⁸Re	¹⁸⁶Re
76	¹⁸⁹Os	¹⁸⁶Os
77	¹⁹⁰Ir	¹⁸⁶Ir
78	¹⁹¹Pt	¹⁸⁶Pt
79	¹⁹²Au	¹⁸⁶Au
80	¹⁹³Hg	¹⁸⁶Hg
81	¹⁹⁴Tl	¹⁸⁶Tl
82	¹⁹⁵Pb	¹⁸⁶Pb
83	¹⁹⁶Bi	¹⁸⁶Bi
84	¹⁹⁷Po	¹⁸⁶Po
85	¹⁹⁸At
86	¹⁹⁹Rn
87	²⁰⁰Fr
88	²⁰¹Ra