Mercury-203m

Properties and data of the isotope ^203mHg.

Contents

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

General data

Name of the isotope:Mercury-203m; Hg-203mSymbol:^203mHg or 203m80HgMass number A:203 (= number of nucleons)Atomic number Z:80 (= number of protons)Neutrons N:123Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.5375 (= neutron-proton ratio)Neutron excess (N-Z):43Excitation energy:933.14(23) keVIsotopic mass:202.9728724(18) u (atomic weight of Mercury-203m)Nuclide mass:202.9289908 u (calculated nuclear mass without electrons)Mass excess:-25.2692 MeVMass defect:1.718914828 u (per nucleus)Nuclear binding energy:1601.15884879 MeV (per nucleus)
7.88748201 MeV (average binding energy per nucleon)Half-life:24(4) μsDecay constant λ:28881.132523331 s^-1Specific activity α:8.568940435594 × 10⁺²⁵ Bq g^-1
2.31592984745 × 10⁺¹⁵ Ci g^-1Spin and parity:
(nuclear angular momentum)

Radioactive Decay

Half-life T_½ = 24(4) μs respectively 2.4 × 10^-5 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²⁰³Hg	100 %

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
²⁰³Hg		46.610(10) d	5/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 123) and isobaric (same nucleon number A = 203) with Mercury-203m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 123	Isobar A = 203
74	¹⁹⁷W
75	¹⁹⁸Re
76	¹⁹⁹Os	²⁰³Os
77	²⁰⁰Ir	²⁰³Ir
78	²⁰¹Pt	²⁰³Pt
79	²⁰²Au	²⁰³Au
80	²⁰³Hg	²⁰³Hg
81	²⁰⁴Tl	²⁰³Tl
82	²⁰⁵Pb	²⁰³Pb
83	²⁰⁶Bi	²⁰³Bi
84	²⁰⁷Po	²⁰³Po
85	²⁰⁸At	²⁰³At
86	²⁰⁹Rn	²⁰³Rn
87	²¹⁰Fr	²⁰³Fr
88	²¹¹Ra	²⁰³Ra
89	²¹²Ac	²⁰³Ac
90	²¹³Th
91	²¹⁴Pa
92	²¹⁵U