Thorium-214m

Properties and data of the isotope ²¹⁴Th.

Content

General data

Name of the isotope:Thorium-214m; Th-214mSymbol:²¹⁴Th or 21490ThMass number A:214 (= number of nucleons)Atomic number Z:90 (= number of protons)Neutrons N:124Isotopic mass:214.011481(11) u (atomic weight of Thorium-214m)
Excitation energy: 2181.0(27) keVNuclide mass:213.9621152 u (calculated nuclear mass without electrons)Mass excess:10.69448 MeVMass defect:1.767221464 u (per nucleus)Nuclear binding energy:1646.15619039 MeV (per nucleus)
7.69231865 MeV (average binding energy per nucleon)Half-life:1.24(12) μsDecay constant λ:558989.66174189 s^-1Specific activity α:1.573044150587 × 10⁺²⁷ Bq g^-1
4.251470677264 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)(8+)

Radioactive Decay

Half-life T_½ = 1.24(12) μs respectively 1.24 × 10^-6 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²¹⁴Th	100 %

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
²¹⁴Th		87(10) ms	0+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 124) and isobaric (same nucleon number A = 214) with Thorium-214m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 124	Isobar A = 214
75	¹⁹⁹Re
76	²⁰⁰Os
77	²⁰¹Ir
78	²⁰²Pt
79	²⁰³Au
80	²⁰⁴Hg	²¹⁴Hg
81	²⁰⁵Tl	²¹⁴Tl
82	²⁰⁶Pb	²¹⁴Pb
83	²⁰⁷Bi	²¹⁴Bi
84	²⁰⁸Po	²¹⁴Po
85	²⁰⁹At	²¹⁴At
86	²¹⁰Rn	²¹⁴Rn
87	²¹¹Fr	²¹⁴Fr
88	²¹²Ra	²¹⁴Ra
89	²¹³Ac	²¹⁴Ac
90	²¹⁴Th	²¹⁴Th
91	²¹⁵Pa	²¹⁴Pa
92	²¹⁶U	²¹⁴U