Thorium-223

Properties and data of the isotope ²²³Th.

Content

General data

Name of the isotope:Thorium-223; Th-223Symbol:²²³Th or 22390ThMass number A:223 (= number of nucleons)Atomic number Z:90 (= number of protons)Neutrons N:133Isotopic mass:223.020811(9) u (atomic weight of Thorium-223)Nuclide mass:222.9714452 u (calculated nuclear mass without electrons)Mass excess:19.38532 MeVMass defect:1.835875708 u (per nucleus)Nuclear binding energy:1710.10720675 MeV (per nucleus)
7.66864218 MeV (average binding energy per nucleon)Separation energy:S_N = 5.889(13) MeV (first neutron)
S_P = 4.525(9) MeV (first proton)Half-life:0.60(2) sDecay constant λ:1.1552453009332 s^-1Specific activity α:3.119753331838 × 10⁺²¹ Bq g^-1
84317657617.259 Ci g^-1Spin and parity:
(nuclear angular momentum)(5/2)+Year of discovery:1952

Radioactive Decay

Half-life T_½ = 0.60(2) s respectively 6.0 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²¹⁹Ra	100 %	7.567(4) MeV

Parent Nuclides

Direct parent isotope is: ²²⁷U.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 133) and isobaric (same nucleon number A = 223) with Thorium-223. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 133	Isobar A = 223
80	²¹³Hg
81	²¹⁴Tl
82	²¹⁵Pb
83	²¹⁶Bi	²²³Bi
84	²¹⁷Po	²²³Po
85	²¹⁸At	²²³At
86	²¹⁹Rn	²²³Rn
87	²²⁰Fr	²²³Fr
88	²²¹Ra	²²³Ra
89	²²²Ac	²²³Ac
90	²²³Th	²²³Th
91	²²⁴Pa	²²³Pa
92	²²⁵U	²²³U
93	²²⁶Np