Americium-233

Properties and data of the isotope ²³³Am.

Content

General data

Name of the isotope:Americium-233; Am-233Symbol:²³³Am or 23395AmMass number A:233 (= number of nucleons)Atomic number Z:95 (= number of protons)Neutrons N:138Isotopic mass:233.046470(129) u (atomic weight of Americium-233)Nuclide mass:232.9943621 u (calculated nuclear mass without electrons)Mass excess:43.28653 MeVMass defect:1.892666448 u (per nucleus)Nuclear binding energy:1763.00744031 MeV (per nucleus)
7.56655554 MeV (average binding energy per nucleon)Separation energy:S_N = 8.206(32) MeV (first neutron)
S_P = 2.365(115) MeV (first proton)Half-life:3.2(8) minDecay constant λ:0.0036101415654164 s^-1Specific activity α:9.330807309549 × 10⁺¹⁸ Bq g^-1
252183981.33917 Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2000

Radioactive Decay

Half-life T_½ = 3.2(8) min (minutes) respectively 1.92 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
α	²²⁹Np	4.5 %	7.059(53) MeV
EE/β⁺	²³³Pu	95.5 %	3.233(126) MeV

Parent Nuclides

Direct parent isotope is: ²³³Cm.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 138) and isobaric (same nucleon number A = 233) with Americium-233. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 138	Isobar A = 233
82	²²⁰Pb
83	²²¹Bi
84	²²²Po
85	²²³At
86	²²⁴Rn
87	²²⁵Fr	²³³Fr
88	²²⁶Ra	²³³Ra
89	²²⁷Ac	²³³Ac
90	²²⁸Th	²³³Th
91	²²⁹Pa	²³³Pa
92	²³⁰U	²³³U
93	²³¹Np	²³³Np
94	²³²Pu	²³³Pu
95	²³³Am	²³³Am
96	²³⁴Cm	²³³Cm
97	²³⁵Bk	²³³Bk