Americium-241m

Properties and data of the isotope ^241mAm.

Content

General data

Name of the isotope:Americium-241m; Am-241mSymbol:^241mAm or 241m95AmMass number A:241 (= number of nucleons)Atomic number Z:95 (= number of protons)Neutrons N:146Isotopic mass:241.0568273(12) u (atomic weight of Americium-241m)
Excitation energy: 2200(100) keVNuclide mass:241.0047194 u (calculated nuclear mass without electrons)Mass excess:52.93429 MeVMass defect:1.951628476 u (per nucleus)Nuclear binding energy:1817.93021562 MeV (per nucleus)
7.5432789 MeV (average binding energy per nucleon)Half-life:1.2(3) μsDecay constant λ:577622.65046662 s^-1Specific activity α:1.443371354771 × 10⁺²⁷ Bq g^-1
3.901003661545 × 10⁺¹⁶ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:1969

Radioactive Decay

Half-life T_½ = 1.2(3) μs respectively 1.2 × 10^-6 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
SZ	^div	100 %

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
²⁴¹Am		432.6(6) a	5/2-

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 146) and isobaric (same nucleon number A = 241) with Americium-241m. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 146	Isobar A = 241
87	²³³Fr
88	²³⁴Ra
89	²³⁵Ac
90	²³⁶Th
91	²³⁷Pa
92	²³⁸U	²⁴¹U
93	²³⁹Np	²⁴¹Np
94	²⁴⁰Pu	²⁴¹Pu
95	²⁴¹Am	²⁴¹Am
96	²⁴²Cm	²⁴¹Cm
97	²⁴³Bk	²⁴¹Bk
98	²⁴⁴Cf	²⁴¹Cf
99	²⁴⁵Es	²⁴¹Es
100	²⁴⁶Fm	²⁴¹Fm
101	²⁴⁷Md