Americium-246m1

Properties and data of the isotope ²⁴⁶Am.

Content

General data

Name of the isotope:Americium-246m1; Am-246m1Symbol:²⁴⁶Am or 24695AmMass number A:246 (= number of nucleons)Atomic number Z:95 (= number of protons)Neutrons N:151Isotopic mass:246.069774(19) u (atomic weight of Americium-246m1)Nuclide mass:246.0176661 u (calculated nuclear mass without electrons)Mass excess:64.99406 MeVMass defect:1.982006356 u (per nucleus)Nuclear binding energy:1846.22702858 MeV (per nucleus)
7.50498792 MeV (average binding energy per nucleon)Half-life:25.0(2) minDecay constant λ:0.0004620981203733 s^-1Specific activity α:1.131227630894 × 10⁺¹⁸ Bq g^-1
30573719.7539 Ci g^-1Spin and parity:
(nuclear angular momentum)2(-)

Radioactive Decay

Half-life T_½ = 25.0(2) min (minutes) respectively 1.500 × 10³ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	²⁴⁶Cm	ca. 100 %
Iso	²⁴⁶Am	0.02 %

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
²⁴⁶Am		39(3) min	(7-)
^246m2Am	2000 keV	73(10) µs

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 151) and isobaric (same nucleon number A = 246) with Americium-246m1. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 151	Isobar A = 246
92	²⁴²U
93	²⁴⁴Np
94	²⁴⁵Pu	²⁴⁶Pu
95	²⁴⁶Am	²⁴⁶Am
96	²⁴⁷Cm	²⁴⁶Cm
97	²⁴⁸Bk	²⁴⁶Bk
98	²⁴⁹Cf	²⁴⁶Cf
99	²⁵⁰Es	²⁴⁶Es
100	²⁵¹Fm	²⁴⁶Fm
101	²⁵²Md	²⁴⁶Md
102	²⁵³No
103	²⁵⁴Lr
104	²⁵⁵Rf
105	²⁵⁶Db