Mercury-185m
Properties and data of the isotope 185mHg.
See also: List of individual Mercury isotopes (and general data sources).
General data
Name of the isotope:Mercury-185m; Hg-185mSymbol:185mHg or 185m80HgMass number A:185 (= number of nucleons)Atomic number Z:80 (= number of protons)Neutrons N:105Isotopic mass:184.971891(15) u (atomic weight of Mercury-185m)
Excitation energy: 99.3(5) keVNuclide mass:184.9280094 u (calculated nuclear mass without electrons)Mass excess:-26.18336 MeVMass defect:1.56392774 u (per nucleus)Nuclear binding energy:1456.78930624 MeV (per nucleus)
7.87453679 MeV (average binding energy per nucleon)Half-life:21.6(15) sDecay constant λ:0.032090147248146 s-1Specific activity α:1.05027927687 × 10+20 Bq g-1
2838592640.1946 Ci g-1Spin and parity:
(nuclear angular momentum)13/2+Magnetic dipole moment:μ(μN) = - 1.017(9)Quadrupole moment Q:0.20 barn (100 fm2)Nuclear g-factor:gl = -0.15646153846154
Radioactive Decay
Half-life T½ = 21.6(15) s respectively 2.16 × 101 seconds s.
Decay
mode | Daughter | Probability | Decay energy | γ energy
(intensity) |
|---|
| α | 181Pt | ca. 0.03 % | | |
| EC/β+ | 185Au | 46(10) % | | |
| Iso | 185Hg | 54(10) % | | |
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 |
|---|
| 185Hg | | 49.1(10) s | 1/2- |
Isotones and Isobars
The following table shows the atomic nuclei that are isotonic (same neutron number N = 105) and isobaric (same nucleon number A = 185) with Mercury-185m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
| Z | Isotone N = 105 | Isobar A = 185 |
|---|
| 63 | 168Eu | |
| 64 | 169Gd | |
| 65 | 170Tb | |
| 66 | 171Dy | |
| 67 | 172Ho | |
| 68 | 173Er | |
| 69 | 174Tm | |
| 70 | 175Yb | 185Yb |
| 71 | 176Lu | 185Lu |
| 72 | 177Hf | 185Hf |
| 73 | 178Ta | 185Ta |
| 74 | 179W | 185W |
| 75 | 180Re | 185Re |
| 76 | 181Os | 185Os |
| 77 | 182Ir | 185Ir |
| 78 | 183Pt | 185Pt |
| 79 | 184Au | 185Au |
| 80 | 185Hg | 185Hg |
| 81 | 186Tl | 185Tl |
| 82 | 187Pb | 185Pb |
| 83 | 188Bi | 185Bi |
| 84 | 189Po | |
| 85 | 190At | |
Last update: 2020-10-22
Perma link: https://www.chemlin.org/isotope/mercury-185m
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