Uranium-237m

Properties and data of the isotope ^237mU.

Contents

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

General data

Name of the isotope:Uranium-237m; U-237mSymbol:^237mU or 237m92UMass number A:237 (= number of nucleons)Atomic number Z:92 (= number of protons)Neutrons N:145Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.5760869565217 (= neutron-proton ratio)Neutron excess (N-Z):53Excitation energy:274.0(10) keVIsotopic mass:237.0487284(13) u (atomic weight of Uranium-237m)Nuclide mass:236.9982657 u (calculated nuclear mass without electrons)Mass excess:45.39021 MeVMass defect:1.927587364 u (per nucleus)Nuclear binding energy:1795.53606404 MeV (per nucleus)
7.57610154 MeV (average binding energy per nucleon)Half-life:155(6) nsDecay constant λ:4471917.2939351 s^-1Specific activity α:1.136308685994 × 10⁺²⁸ Bq g^-1
3.071104556741 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)(7/2)-

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
²³⁷U		6.752(2) d	1/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 145) and isobaric (same nucleon number A = 237) with Uranium-237m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 145	Isobar A = 237
87	²³²Fr
88	²³³Ra
89	²³⁴Ac
90	²³⁵Th	²³⁷Th
91	²³⁶Pa	²³⁷Pa
92	²³⁷U	²³⁷U
93	²³⁸Np	²³⁷Np
94	²³⁹Pu	²³⁷Pu
95	²⁴⁰Am	²³⁷Am
96	²⁴¹Cm	²³⁷Cm
97	²⁴²Bk	²³⁷Bk
98	²⁴³Cf	²³⁷Cf
99	²⁴⁴Es
100	²⁴⁵Fm
101	²⁴⁶Md