Francium-232

Properties and data of the isotope ²³²Fr.

Content

General data

Name of the isotope:Francium-232; Fr-232Symbol:²³²Fr or 23287FrMass number A:232 (= number of nucleons)Atomic number Z:87 (= number of protons)Neutrons N:145Isotopic mass:232.049461(15) u (atomic weight of Francium-232)Nuclide mass:232.0017404 u (calculated nuclear mass without electrons)Mass excess:46.07262 MeVMass defect:1.887729604 u (per nucleus)Nuclear binding energy:1758.40879975 MeV (per nucleus)
7.57934827 MeV (average binding energy per nucleon)Separation energy:S_N = 4.079(16) MeV (first neutron)
S_P = 7.67(30) MeV (first proton)Half-life:5.5(6) sDecay constant λ:0.12602676010181 s^-1Specific activity α:3.271340092476 × 10⁺²⁰ Bq g^-1
8841459709.3959 Ci g^-1Spin and parity:
(nuclear angular momentum)(5)Year of discovery:1990

Radioactive Decay

Half-life T_½ = 5.5(6) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²³²Ra	100 %	5.576(17) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 145) and isobaric (same nucleon number A = 232) with Francium-232. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 145	Isobar A = 232
87	²³²Fr	²³²Fr
88	²³³Ra	²³²Ra
89	²³⁴Ac	²³²Ac
90	²³⁵Th	²³²Th
91	²³⁶Pa	²³²Pa
92	²³⁷U	²³²U
93	²³⁸Np	²³²Np
94	²³⁹Pu	²³²Pu
95	²⁴⁰Am	²³²Am
96	²⁴¹Cm	²³²Cm
97	²⁴²Bk
98	²⁴³Cf
99	²⁴⁴Es
100	²⁴⁵Fm
101	²⁴⁶Md