Americium-232

Properties and data of the isotope ²³²Am.

Content

General data

Name of the isotope:Americium-232; Am-232Symbol:²³²Am or 23295AmMass number A:232 (= number of nucleons)Atomic number Z:95 (= number of protons)Neutrons N:137Isotopic mass:232.04653(32) u (atomic weight of Americium-232)Nuclide mass:231.9944221 u (calculated nuclear mass without electrons)Mass excess:43.34242 MeVMass defect:1.883941532 u (per nucleus)Nuclear binding energy:1754.88023341 MeV (per nucleus)
7.56413894 MeV (average binding energy per nucleon)Separation energy:S_N = 7.14(42) MeV (first neutron)
S_P = 2.26(30) MeV (first proton)Half-life:79(2) sDecay constant λ:0.0087740149437968 s^-1Specific activity α:2.277515254255 × 10⁺¹⁹ Bq g^-1
615544663.31238 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1967

Radioactive Decay

Half-life T_½ = 79(2) s respectively 7.9 × 10¹ seconds s.

Decay mode	Daughter	Probability	Decay energy
EE	²³²Pu	ca. 97 %	4.98(30) MeV
α	²²⁸Np	ca. 3 %	7.32(30) MeV
EE/F	^div	0.069(10) %

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 137) and isobaric (same nucleon number A = 232) with Americium-232. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 137	Isobar A = 232
82	²¹⁹Pb
83	²²⁰Bi
84	²²¹Po
85	²²²At
86	²²³Rn
87	²²⁴Fr	²³²Fr
88	²²⁵Ra	²³²Ra
89	²²⁶Ac	²³²Ac
90	²²⁷Th	²³²Th
91	²²⁸Pa	²³²Pa
92	²²⁹U	²³²U
93	²³⁰Np	²³²Np
94	²³¹Pu	²³²Pu
95	²³²Am	²³²Am
96	²³³Cm	²³²Cm
97	²³⁴Bk