Curium-243

Properties and data of the isotope ²⁴³Cm.

Content

General data

Name of the isotope:Curium-243; Cm-243Symbol:²⁴³Cm or 24396CmMass number A:243 (= number of nucleons)Atomic number Z:96 (= number of protons)Neutrons N:147Isotopic mass:243.0613874(16) u (atomic weight of Curium-243)Nuclide mass:243.0087311 u (calculated nuclear mass without electrons)Mass excess:57.18199 MeVMass defect:1.963558324 u (per nucleus)Nuclear binding energy:1829.04279746 MeV (per nucleus)
7.52692509 MeV (average binding energy per nucleon)Separation energy:S_N = 5.6931(10) MeV (first neutron)
S_P = 5.575(1) MeV (first proton)Half-life:29.1(1) aDecay constant λ:7.553091212378 × 10^-10 s^-1Specific activity α:1871842765798 Bq g^-1
50.590345021568 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2+Magnetic dipole moment:μ(μ_N) = 0.41Nuclear g-factor:g_l = 0.164Year of discovery:1950

Radioactive Decay

Half-life T_½ = 29.1(1) a respectively 9.177 × 10⁸ seconds s.

Decay mode	Daughter	Probability	Decay energy
α	²³⁹Pu	99.71(3) %	6.1688(10) MeV
EE	²⁴³Am	0.29(3) %	0.007(2) MeV
SZ	^div	trace

Parent Nuclides

Direct parent isotopes are: ²⁴⁷Cf, ²⁴³Bk.

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
^243mCm	87.4(1) keV	1.08(3) μs	1/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 147) and isobaric (same nucleon number A = 243) with Curium-243. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 147	Isobar A = 243
89	²³⁶Ac
90	²³⁷Th
91	²³⁸Pa
92	²³⁹U
93	²⁴⁰Np	²⁴³Np
94	²⁴¹Pu	²⁴³Pu
95	²⁴²Am	²⁴³Am
96	²⁴³Cm	²⁴³Cm
97	²⁴⁴Bk	²⁴³Bk
98	²⁴⁵Cf	²⁴³Cf
99	²⁴⁶Es	²⁴³Es
100	²⁴⁷Fm	²⁴³Fm
101	²⁴⁸Md