Thorium-236

Properties and data of the isotope ²³⁶Th.

Content

General data

Name of the isotope:Thorium-236; Th-236Symbol:²³⁶Th or 23690ThMass number A:236 (= number of nucleons)Atomic number Z:90 (= number of protons)Neutrons N:146Isotopic mass:236.049657(15) u (atomic weight of Thorium-236)Nuclide mass:236.0002912 u (calculated nuclear mass without electrons)Mass excess:46.2552 MeVMass defect:1.919673616 u (per nucleus)Nuclear binding energy:1788.16445526 MeV (per nucleus)
7.57696803 MeV (average binding energy per nucleon)Separation energy:S_N = 5.834(19) MeV (first neutron)
S_P = 8.391(20) MeV (first proton)Half-life:37.5(2) minDecay constant λ:0.0003080654135822 s^-1Specific activity α:7.861073367231 × 10⁺¹⁷ Bq g^-1
21246144.235761 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1973

Radioactive Decay

Half-life T_½ = 37.5(2) min (minutes) respectively 2.250 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²³⁶Pa	100 %	0.921(20) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 146) and isobaric (same nucleon number A = 236) with Thorium-236. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 146	Isobar A = 236
87	²³³Fr
88	²³⁴Ra
89	²³⁵Ac	²³⁶Ac
90	²³⁶Th	²³⁶Th
91	²³⁷Pa	²³⁶Pa
92	²³⁸U	²³⁶U
93	²³⁹Np	²³⁶Np
94	²⁴⁰Pu	²³⁶Pu
95	²⁴¹Am	²³⁶Am
96	²⁴²Cm	²³⁶Cm
97	²⁴³Bk	²³⁶Bk
98	²⁴⁴Cf
99	²⁴⁵Es
100	²⁴⁶Fm
101	²⁴⁷Md