Thorium-224

Properties and data of the isotope ²²⁴Th.

Content

General data

Name of the isotope:Thorium-224; Th-224Symbol:²²⁴Th or 22490ThMass number A:224 (= number of nucleons)Atomic number Z:90 (= number of protons)Neutrons N:134Isotopic mass:224.021464(11) u (atomic weight of Thorium-224)Nuclide mass:223.9720982 u (calculated nuclear mass without electrons)Mass excess:19.99359 MeVMass defect:1.843887624 u (per nucleus)Nuclear binding energy:1717.57025843 MeV (per nucleus)
7.66772437 MeV (average binding energy per nucleon)Separation energy:S_N = 7.463(14) MeV (first neutron)
S_P = 5.121(12) MeV (first proton)Half-life:1.04(2) sDecay constant λ:0.66648767361533 s^-1Specific activity α:1.791822612465 × 10⁺²¹ Bq g^-1
48427638174.749 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1949

Radioactive Decay

Half-life T_½ = 1.04(2) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²²⁰Ra	100 %	7.299(6) MeV

Parent Nuclides

Direct parent isotope is: ²²⁸U.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 134) and isobaric (same nucleon number A = 224) with Thorium-224. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 134	Isobar A = 224
80	²¹⁴Hg
81	²¹⁵Tl
82	²¹⁶Pb
83	²¹⁷Bi	²²⁴Bi
84	²¹⁸Po	²²⁴Po
85	²¹⁹At	²²⁴At
86	²²⁰Rn	²²⁴Rn
87	²²¹Fr	²²⁴Fr
88	²²²Ra	²²⁴Ra
89	²²³Ac	²²⁴Ac
90	²²⁴Th	²²⁴Th
91	²²⁵Pa	²²⁴Pa
92	²²⁶U	²²⁴U
93	²²⁷Np
94	²²⁸Pu
95	²²⁹Am