Mercury-188m

Properties and data of the isotope ¹⁸⁸Hg.

Content

General data

Name of the isotope:Mercury-188m; Hg-188mSymbol:¹⁸⁸Hg or 18880HgMass number A:188 (= number of nucleons)Atomic number Z:80 (= number of protons)Neutrons N:108Isotopic mass:187.967577(13) u (atomic weight of Mercury-188m)
Excitation energy: 2724.1(4) keVNuclide mass:187.9236954 u (calculated nuclear mass without electrons)Mass excess:-30.20183 MeVMass defect:1.594236488 u (per nucleus)Nuclear binding energy:1485.02172315 MeV (per nucleus)
7.89905172 MeV (average binding energy per nucleon)Half-life:154(20) nsDecay constant λ:4500955.7179217 s^-1Specific activity α:1.449486060837 × 10⁺²⁸ Bq g^-1
3.917529894155 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)12+Magnetic dipole moment:μ(μ_N) = -2.02(12)Quadrupole moment Q:0.91(11) barn (100 fm²)Nuclear g-factor:g_l = -0.16833333333333

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
¹⁸⁸Hg		3.25(15) min	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 108) and isobaric (same nucleon number A = 188) with Mercury-188m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 108	Isobar A = 188
66	¹⁷⁴Dy
67	¹⁷⁵Ho
68	¹⁷⁶Er
69	¹⁷⁷Tm
70	¹⁷⁸Yb
71	¹⁷⁹Lu	¹⁸⁸Lu
72	¹⁸⁰Hf	¹⁸⁸Hf
73	¹⁸¹Ta	¹⁸⁸Ta
74	¹⁸²W	¹⁸⁸W
75	¹⁸³Re	¹⁸⁸Re
76	¹⁸⁴Os	¹⁸⁸Os
77	¹⁸⁵Ir	¹⁸⁸Ir
78	¹⁸⁶Pt	¹⁸⁸Pt
79	¹⁸⁷Au	¹⁸⁸Au
80	¹⁸⁸Hg	¹⁸⁸Hg
81	¹⁸⁹Tl	¹⁸⁸Tl
82	¹⁹⁰Pb	¹⁸⁸Pb
83	¹⁹¹Bi	¹⁸⁸Bi
84	¹⁹²Po	¹⁸⁸Po
85	¹⁹³At
86	¹⁹⁴Rn