Radium-213

Properties and data of the isotope ²¹³Ra.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

See also: List of individual Radium isotopes (and general data sources).

General data

Name of the isotope:Radium-213; Ra-213Symbol: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-213)Nuclide 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)Separation energy:S_N = 7.527(14) MeV (first neutron)
S_P = 3.427(13) MeV (first proton)Half-life:2.73(5) minDecay constant λ:0.0042316677689862 s^-1Specific activity α:1.196417811140 × 10⁺¹⁹ Bq g^-1
323356165.17305 Ci g^-1Spin and parity:
(nuclear angular momentum)1/2-Magnetic dipole moment:μ(μ_N) = + 0.610(2)Nuclear g-factor:g_l = 1.22Charge radius:5.6020(177) femtometer fmYear of discovery:1955

Radioactive Decay

Half-life T_½ = 2.73(5) min (minutes) respectively 1.638 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁰⁹Rn	86(2) %	6.8617(23) MeV
EC/β⁺	²¹³Fr	14(2) %	3.900(11) MeV

Parent Nuclides

Direct parent isotopes are: ²¹⁷Th, ²¹³Ac.

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
^213mRa	1770(7) keV	2.15(7) ms	(17/2-)

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-213. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	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