Mercury-195m

Properties and data of the isotope ^195mHg.

Contents

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

General data

Name of the isotope:Mercury-195m; Hg-195mSymbol:^195mHg or 195m80HgMass number A:195 (= number of nucleons)Atomic number Z:80 (= number of protons)Neutrons N:115Isotopic mass:194.966706(25) u (atomic weight of Mercury-195m)
Excitation energy: 176.07(4) keVNuclide mass:194.9228244 u (calculated nuclear mass without electrons)Mass excess:-31.01316 MeVMass defect:1.6557619 u (per nucleus)Nuclear binding energy:1542.33227528 MeV (per nucleus)
7.90939628 MeV (average binding energy per nucleon)Half-life:41.6(8) hDecay constant λ:4.628386622328 × 10^-6 s^-1Specific activity α:1.43674207185 × 10⁺¹⁶ Bq g^-1
388308.66806784 Ci g^-1Spin and parity:
(nuclear angular momentum)13/2+Magnetic dipole moment:μ(μ_N) = - 1.00446473(26)Quadrupole moment Q:1.08(11) barn (100 fm²)Nuclear g-factor:g_l = -0.15453303538462

Radioactive Decay

Half-life T_½ = 41.6(8) h (hours) respectively 1.49760 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁹⁵Au	45.8(20) %
Iso	¹⁹⁵Hg	54.2(20) %

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
¹⁹⁵Hg		10.53(3) h	1/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 115) and isobaric (same nucleon number A = 195) with Mercury-195m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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