Uranium-239m2

Properties and data of the isotope ^239m2U.

Contents

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

General data

Name of the isotope:Uranium-239m2; U-239m2Symbol:^239m2U or 239m292UMass number A:239 (= number of nucleons)Atomic number Z:92 (= number of protons)Neutrons N:147Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.5978260869565 (= neutron-proton ratio)Neutron excess (N-Z):55Excitation energy:+x keVIsotopic mass:239.0542920(16) u (atomic weight of Uranium-239m2)Nuclide mass:239.0038293 u (calculated nuclear mass without electrons)Mass excess:50.57267 MeVMass defect:1.939353596 u (per nucleus)Nuclear binding energy:1806.49623855 MeV (per nucleus)
7.55856167 MeV (average binding energy per nucleon)Half-life:0.25 μsDecay constant λ:2772588.7222398 s^-1Specific activity α:6.98615892552 × 10⁺²⁷ Bq g^-1
1.888151060952 × 10⁺¹⁷ Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2+)

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
^239m1U	133.7991(10) keV	0.78(4) μs	1/2+
²³⁹U		23.45(2) min	5/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 147) and isobaric (same nucleon number A = 239) with Uranium-239m2. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 147	Isobar A = 239
89	²³⁶Ac
90	²³⁷Th
91	²³⁸Pa	²³⁹Pa
92	²³⁹U	²³⁹U
93	²⁴⁰Np	²³⁹Np
94	²⁴¹Pu	²³⁹Pu
95	²⁴²Am	²³⁹Am
96	²⁴³Cm	²³⁹Cm
97	²⁴⁴Bk	²³⁹Bk
98	²⁴⁵Cf	²³⁹Cf
99	²⁴⁶Es
100	²⁴⁷Fm
101	²⁴⁸Md
102	²⁴⁹No