Uranium-234

Properties and data of the isotope ²³⁴U.

Contents

Uranium-234 is the radioisotope of the element uranium, whose atomic nucleus has 92 protons and 142 neutrons, which results in a mass number of 234.

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

General data

Name of the isotope:Uranium-234; U-234Other names:Uran II. Uranium IISymbol:²³⁴U or 23492UMass number A:234 (= number of nucleons)Atomic number Z:92 (= number of protons)Neutrons N:142Nucleon pairing (Z - N):even - evenNuclear ratio (N/Z ratio):1.5434782608696 (= neutron-proton ratio)Neutron excess (N-Z):50Isotopic mass:234.04095(2) u (atomic weight of Uranium-234)Nuclide mass:233.9904873 u (calculated nuclear mass without electrons)Mass excess:38.14468 MeVMass defect:1.909371016 u (per nucleus)Nuclear binding energy:1778.56764518 MeV (per nucleus)
7.60071643 MeV (average binding energy per nucleon)Separation energy:S_N = 6.8455(20) MeV (first neutron)
S_P = 6.6334(8) MeV (first proton)Half-life:2.455(6) × 10⁵ aDecay constant λ:8.952974708630 × 10^-14 s^-1Specific activity α:230410576.11464 Bq g^-1
0.0062273128679632 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1912

Radioactive Decay

Half-life T_½ = 2.455(6) × 10⁵ a respectively 7.742088 × 10¹² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²³⁰Th	ca. 100 %	4.8575(7) MeV
SZ	div	trace

The figure shows the natural decay scheme for the nuclide uranium-234, whose endpoint is the stable lead nuclide lead-206.

Parent Nuclides

Direct parent isotopes are: ²³⁸Pu, ²³⁴Np, ²³⁴Pa, ^234mPa.

Occurrence

Comparison of the natural Uranium isotopes including isotopic abundance (mole fraction of the isotope mixture in percent):

	Atomic Mass m_a	Quantity	Half-life	Spin
Uranium Isotopic mixture	238.02891 u	100 %
Isotope ²³⁴U	234.04095(2) u	0.0054(5) %	2.455(6) × 10⁵ a	0+
Isotope ²³⁵U	235.04393(2) u	0.7204(6) %	7.04(1) × 10⁸ a	7/2-
Isotope ²³⁸U	238.050787618(15) u	99.2742(10) %	4.468(6) × 10⁹ a	0+

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
^234mU	1421.257(17) keV	33.5(20) μs	6-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 142) and isobaric (same nucleon number A = 234) with Uranium-234. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 142	Isobar A = 234
84	²²⁶Po
85	²²⁷At
86	²²⁸Rn
87	²²⁹Fr
88	²³⁰Ra	²³⁴Ra
89	²³¹Ac	²³⁴Ac
90	²³²Th	²³⁴Th
91	²³³Pa	²³⁴Pa
92	²³⁴U	²³⁴U
93	²³⁵Np	²³⁴Np
94	²³⁶Pu	²³⁴Pu
95	²³⁷Am	²³⁴Am
96	²³⁸Cm	²³⁴Cm
97	²³⁹Bk	²³⁴Bk
98	²⁴⁰Cf
99	²⁴¹Es
100	²⁴²Fm