Thorium-216m3

Properties and data of the isotope ²¹⁶Th.

Content

General data

Name of the isotope:Thorium-216m3; Th-216m3Symbol:²¹⁶Th or 21690ThMass number A:216 (= number of nucleons)Atomic number Z:90 (= number of protons)Neutrons N:126Isotopic mass:216.011056(13) u (atomic weight of Thorium-216m3)
Excitation energy: 3681.4(7) keVNuclide mass:215.9616902 u (calculated nuclear mass without electrons)Mass excess:10.2986 MeVMass defect:1.784976296 u (per nucleus)Nuclear binding energy:1662.69470987 MeV (per nucleus)
7.69766069 MeV (average binding energy per nucleon)Half-life:0.74(7) μsDecay constant λ:936685.37913506 s^-1Specific activity α:2.61150522897 × 10⁺²⁷ Bq g^-1
7.058122240483 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)(14+)

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
²¹⁶Th		26.0(2) ms	0+
^216m1Th	2040(9) keV	134(4) μs	8+
^216m2Th	2646.8(1) keV	0.58(3) μs	11-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 126) and isobaric (same nucleon number A = 216) with Thorium-216m3. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 126	Isobar A = 216
76	²⁰²Os
77	²⁰³Ir
78	²⁰⁴Pt
79	²⁰⁵Au
80	²⁰⁶Hg	²¹⁶Hg
81	²⁰⁷Tl	²¹⁶Tl
82	²⁰⁸Pb	²¹⁶Pb
83	²⁰⁹Bi	²¹⁶Bi
84	²¹⁰Po	²¹⁶Po
85	²¹¹At	²¹⁶At
86	²¹²Rn	²¹⁶Rn
87	²¹³Fr	²¹⁶Fr
88	²¹⁴Ra	²¹⁶Ra
89	²¹⁵Ac	²¹⁶Ac
90	²¹⁶Th	²¹⁶Th
91	²¹⁷Pa	²¹⁶Pa
92	²¹⁸U	²¹⁶U
93	²¹⁹Np