Tantalum-180m

Properties and data of the isotope ^180mTa.

Content

General data

Name of the isotope:Tantalum-180m; Ta-180mSymbol:^180mTa or 180m73TaMass number A:180 (= number of nucleons)Atomic number Z:73 (= number of protons)Neutrons N:107Isotopic mass:179.9474684(21) u (atomic weight of Tantalum-180m)
Excitation energy: 76.79(55) keVNuclide mass:179.907426 u (calculated nuclear mass without electrons)Mass excess:-48.93287 MeVMass defect:1.550904948 u (per nucleus)Nuclear binding energy:1444.65865363 MeV (per nucleus)
8.02588141 MeV (average binding energy per nucleon)Half-life:7.1 × 10¹⁵ aDecay constant λ:3.09571167742 × 10^-24 s^-1Specific activity α:0.010414978649821 Bq g^-1
2.814859094546 × 10^-13 Ci g^-1Spin and parity:
(nuclear angular momentum)9-Magnetic dipole moment:μ(μ_N) = 4.825(11)

Occurrence

Comparison of the natural Tantalum isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Tantalum Isotopic mixture	180.94788 u	100 %
Isotope ¹⁸⁰Ta	179.9474684(21) u	0.01201(32) %	7.1 × 10¹⁵ a	9-
Isotope ¹⁸¹Ta	180.94800(2) u	99.98799(32) %	stable	7/2+

NMR data

Nuclear magnetic properties of the NMR active Nuclide ¹⁸⁰Ta

Isotope:¹⁸⁰Ta-NMRQuantity:0.01201(32) %Spin:9-Nuclearmagnetic moment
μ/μ_N:4.825(11)Nuclear g-factor:g_l = 0.53611111111111Quadrupole moment Q:+ 4.95(2) barn (100 fm²)

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
¹⁸⁰Ta		8.154(6) h	1+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 107) and isobaric (same nucleon number A = 180) with Tantalum-180m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 107	Isobar A = 180
65	¹⁷²Tb
66	¹⁷³Dy
67	¹⁷⁴Ho
68	¹⁷⁵Er
69	¹⁷⁶Tm
70	¹⁷⁷Yb	¹⁸⁰Yb
71	¹⁷⁸Lu	¹⁸⁰Lu
72	¹⁷⁹Hf	¹⁸⁰Hf
73	¹⁸⁰Ta	¹⁸⁰Ta
74	¹⁸¹W	¹⁸⁰W
75	¹⁸²Re	¹⁸⁰Re
76	¹⁸³Os	¹⁸⁰Os
77	¹⁸⁴Ir	¹⁸⁰Ir
78	¹⁸⁵Pt	¹⁸⁰Pt
79	¹⁸⁶Au	¹⁸⁰Au
80	¹⁸⁷Hg	¹⁸⁰Hg
81	¹⁸⁸Tl	¹⁸⁰Tl
82	¹⁸⁹Pb	¹⁸⁰Pb
83	¹⁹⁰Bi
84	¹⁹¹Po
85	¹⁹²At
86	¹⁹³Rn

Literature and References

[1] - C. B. Collins, C. D. Eberhard, J. W. Glesener, J. A. Anderson:
Depopulation of the isomeric state ^180mTa by the reaction ¹⁸⁰Ta^m(γ,γ´)¹⁸⁰Ta.
In: Physical Review C, (1988), DOI 10.1103/PhysRevC.37.2267.

[2] - B. Lehnert, M. Hult, G. Lutter, K. Zuber:
Search for the decay of nature's rarest isotope ^180mTa.
In: Physical Review C, (2017), DOI 10.1103/PhysRevC.95.044306.