Thorium-234

Properties and data of the isotope ²³⁴Th.

Content

General data

Name of the isotope:Thorium-234; Th-234Other names:Uran X1. Uranium X1Symbol:²³⁴Th or 23490ThMass number A:234 (= number of nucleons)Atomic number Z:90 (= number of protons)Neutrons N:144Isotopic mass:234.0435999(28) u (atomic weight of Thorium-234)Nuclide mass:233.9942341 u (calculated nuclear mass without electrons)Mass excess:40.61305 MeVMass defect:1.908400884 u (per nucleus)Nuclear binding energy:1777.66397304 MeV (per nucleus)
7.59685459 MeV (average binding energy per nucleon)Separation energy:S_N = 6.1900(26) MeV (first neutron)
S_P = 7.984(13) MeV (first proton)Cross section:σ(n.γ) = 1.8(5) barn (thermal neutron capture cross-section)
σ(n.f) < 0.01 b (gap cross-section)Half-life:24.10(3) dDecay constant λ:3.328853448977 × 10^-7 s^-1Specific activity α:8.567018962320 × 10⁺¹⁴ Bq g^-1
23154.105303569 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1900

Radioactive Decay

Half-life T_½ = 24.10(3) d respectively 2.082240 × 10⁶ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²³⁴Pa	100 %	0.274(3) MeV

Parent Nuclides

Direct parent isotopes are: ²³⁸U, ²³⁴Ac.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 144) and isobaric (same nucleon number A = 234) with Thorium-234. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 144	Isobar A = 234
85	²²⁹At
86	²³⁰Rn
87	²³¹Fr
88	²³²Ra	²³⁴Ra
89	²³³Ac	²³⁴Ac
90	²³⁴Th	²³⁴Th
91	²³⁵Pa	²³⁴Pa
92	²³⁶U	²³⁴U
93	²³⁷Np	²³⁴Np
94	²³⁸Pu	²³⁴Pu
95	²³⁹Am	²³⁴Am
96	²⁴⁰Cm	²³⁴Cm
97	²⁴¹Bk	²³⁴Bk
98	²⁴²Cf
99	²⁴³Es
100	²⁴⁴Fm
101	²⁴⁵Md