Mercury-191

Properties and data of the isotope ¹⁹¹Hg.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

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

General data

Name of the isotope:Mercury-191; Hg-191Symbol:¹⁹¹Hg or 19180HgMass number A:191 (= number of nucleons)Atomic number Z:80 (= number of protons)Neutrons N:111Isotopic mass:190.967158(24) u (atomic weight of Mercury-191)Nuclide mass:190.9232764 u (calculated nuclear mass without electrons)Mass excess:-30.59213 MeVMass defect:1.620650236 u (per nucleus)Nuclear binding energy:1509.62597093 MeV (per nucleus)
7.90380089 MeV (average binding energy per nucleon)Separation energy:S_N = 7.293(27) MeV (first neutron)
S_P = 5.047(23) MeV (first proton)Half-life:49(10) minDecay constant λ:0.00023576434712923 s^-1Specific activity α:7.472663727175 × 10⁺¹⁷ Bq g^-1
20196388.451825 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2(-)Year of discovery:1954

Radioactive Decay

Half-life T_½ = 49(10) min (minutes) respectively 2.940 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	¹⁹¹Au	100 %	3.206(23) MeV

Parent Nuclides

Direct parent isotope is: ¹⁹¹Tl.

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
^191mHg	+x keV	50.8(15) min	13/2(+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 111) and isobaric (same nucleon number A = 191) with Mercury-191. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 111	Isobar A = 191
70	¹⁸¹Yb
71	¹⁸²Lu
72	¹⁸³Hf
73	¹⁸⁴Ta	¹⁹¹Ta
74	¹⁸⁵W	¹⁹¹W
75	¹⁸⁶Re	¹⁹¹Re
76	¹⁸⁷Os	¹⁹¹Os
77	¹⁸⁸Ir	¹⁹¹Ir
78	¹⁸⁹Pt	¹⁹¹Pt
79	¹⁹⁰Au	¹⁹¹Au
80	¹⁹¹Hg	¹⁹¹Hg
81	¹⁹²Tl	¹⁹¹Tl
82	¹⁹³Pb	¹⁹¹Pb
83	¹⁹⁴Bi	¹⁹¹Bi
84	¹⁹⁵Po	¹⁹¹Po
85	¹⁹⁶At	¹⁹¹At
86	¹⁹⁷Rn