Radium-211

Properties and data of the isotope ²¹¹Ra.

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-211; Ra-211Symbol:²¹¹Ra or 21188RaMass number A:211 (= number of nucleons)Atomic number Z:88 (= number of protons)Neutrons N:123Nucleon pairing (Z - N):even - oddNuclear ratio (N/Z ratio):1.3977272727273 (= neutron-proton ratio)Neutron excess (N-Z):35Isotopic mass:211.000893(8) u (atomic weight of Radium-211)Nuclide mass:210.952624 u (calculated nuclear mass without electrons)Mass excess:0.83182 MeVMass defect:1.753494484 u (per nucleus)Nuclear binding energy:1633.36959088 MeV (per nucleus)
7.74108811 MeV (average binding energy per nucleon)Separation energy:S_N = 7.682(12) MeV (first neutron)
S_P = 3.124(17) MeV (first proton)Half-life:13(2) sDecay constant λ:0.053319013889227 s^-1Specific activity α:1.521775413051 × 10⁺²⁰ Bq g^-1
4112906521.7605 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2(-)Magnetic dipole moment:μ(μ_N) = + 0.8780(38)Quadrupole moment Q:+ 0.46(5) barn (100 fm²)Nuclear g-factor:g_l = 0.3512Charge radius:5.5929(179) femtometer fmYear of discovery:1967

Radioactive Decay

Half-life T_½ = 13(2) s respectively 1.3 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²⁰⁷Rn	93 %	7.042(3) MeV
EC/β⁺	²¹¹Fr	7 %	4.972(14) MeV

Parent Nuclides

Direct parent isotopes are: ²¹⁵Th, ²¹¹Ac.

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
^211mRa	1198.1(8) keV	9.7(6) μs	(13/2+)

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 123) and isobaric (same nucleon number A = 211) with Radium-211. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 123	Isobar A = 211
74	¹⁹⁷W
75	¹⁹⁸Re
76	¹⁹⁹Os
77	²⁰⁰Ir
78	²⁰¹Pt
79	²⁰²Au
80	²⁰³Hg	²¹¹Hg
81	²⁰⁴Tl	²¹¹Tl
82	²⁰⁵Pb	²¹¹Pb
83	²⁰⁶Bi	²¹¹Bi
84	²⁰⁷Po	²¹¹Po
85	²⁰⁸At	²¹¹At
86	²⁰⁹Rn	²¹¹Rn
87	²¹⁰Fr	²¹¹Fr
88	²¹¹Ra	²¹¹Ra
89	²¹²Ac	²¹¹Ac
90	²¹³Th	²¹¹Th
91	²¹⁴Pa
92	²¹⁵U