Mercury-189m

Properties and data of the isotope ^189mHg.

Contents

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

General data

Name of the isotope:Mercury-189m; Hg-189mSymbol:^189mHg or 189m80HgMass number A:189 (= number of nucleons)Atomic number Z:80 (= number of protons)Neutrons N:109Isotopic mass:188.96819(3) u (atomic weight of Mercury-189m)
Excitation energy: +x keVNuclide mass:188.9243084 u (calculated nuclear mass without electrons)Mass excess:-29.63082 MeVMass defect:1.602288404 u (per nucleus)Nuclear binding energy:1492.5220346 MeV (per nucleus)
7.89694198 MeV (average binding energy per nucleon)Half-life:8.6(2) minDecay constant λ:0.0013433084894573 s^-1Specific activity α:4.302974969074 × 10⁺¹⁸ Bq g^-1
116296620.7858 Ci g^-1Spin and parity:
(nuclear angular momentum)13/2+Magnetic dipole moment:μ(μ_N) = -1.058(6)Quadrupole moment Q:+0.66(19) barn (100 fm²)Nuclear g-factor:g_l = -0.16276923076923

Radioactive Decay

Half-life T_½ = 8.6(2) min (minutes) respectively 5.16 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	¹⁸⁵Pt	< 0.00003 %
EC/β⁺	¹⁸⁹Au	> 99.9999 %

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
¹⁸⁹Hg		7.6(2) min	3/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 109) and isobaric (same nucleon number A = 189) with Mercury-189m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 109	Isobar A = 189
68	¹⁷⁷Er
69	¹⁷⁸Tm
70	¹⁷⁹Yb
71	¹⁸⁰Lu
72	¹⁸¹Hf	¹⁸⁹Hf
73	¹⁸²Ta	¹⁸⁹Ta
74	¹⁸³W	¹⁸⁹W
75	¹⁸⁴Re	¹⁸⁹Re
76	¹⁸⁵Os	¹⁸⁹Os
77	¹⁸⁶Ir	¹⁸⁹Ir
78	¹⁸⁷Pt	¹⁸⁹Pt
79	¹⁸⁸Au	¹⁸⁹Au
80	¹⁸⁹Hg	¹⁸⁹Hg
81	¹⁹⁰Tl	¹⁸⁹Tl
82	¹⁹¹Pb	¹⁸⁹Pb
83	¹⁹²Bi	¹⁸⁹Bi
84	¹⁹³Po	¹⁸⁹Po
85	¹⁹⁴At	¹⁸⁹At
86	¹⁹⁵Rn