Radium-213m

Properties and data of the isotope ²¹³Ra.

Content

General data

Name of the isotope:Radium-213m; Ra-213mSymbol:²¹³Ra or 21388RaMass number A:213 (= number of nucleons)Atomic number Z:88 (= number of protons)Neutrons N:125Isotopic mass:213.000371(11) u (atomic weight of Radium-213m)
Excitation energy: 1770(7) keVNuclide mass:212.952102 u (calculated nuclear mass without electrons)Mass excess:0.34558 MeVMass defect:1.771346316 u (per nucleus)Nuclear binding energy:1649.99846528 MeV (per nucleus)
7.74647167 MeV (average binding energy per nucleon)Half-life:2.15(7) msDecay constant λ:322.39403746974 s^-1Specific activity α:9.115034300687 × 10⁺²³ Bq g^-1
24635227839697 Ci g^-1Spin and parity:
(nuclear angular momentum)(17/2-)Magnetic dipole moment:μ(μ_N) = 7.4Nuclear g-factor:g_l = 0.87058823529412

Radioactive Decay

Half-life T_½ = 2.15(7) ms respectively 2.15 × 10^-3 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
Iso	²¹³Ra	99 %
α	²⁰⁹Ra	1 %

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
²¹³Ra		2.73(5) min	1/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 125) and isobaric (same nucleon number A = 213) with Radium-213m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 125	Isobar A = 213
76	²⁰¹Os
77	²⁰²Ir
78	²⁰³Pt
79	²⁰⁴Au
80	²⁰⁵Hg	²¹³Hg
81	²⁰⁶Tl	²¹³Tl
82	²⁰⁷Pb	²¹³Pb
83	²⁰⁸Bi	²¹³Bi
84	²⁰⁹Po	²¹³Po
85	²¹⁰At	²¹³At
86	²¹¹Rn	²¹³Rn
87	²¹²Fr	²¹³Fr
88	²¹³Ra	²¹³Ra
89	²¹⁴Ac	²¹³Ac
90	²¹⁵Th	²¹³Th
91	²¹⁶Pa	²¹³Pa
92	²¹⁷U