Aluminium-40

Properties and data of the isotope ⁴⁰Al.

Content

General data

Name of the isotope:Aluminium-40; Al-40Symbol:⁴⁰Al or 4013AlMass number A:40 (= number of nucleons)Atomic number Z:13 (= number of protons)Neutrons N:27Isotopic mass:40.02962(43) u (atomic weight of Aluminium-40)Nuclide mass:40.0224885 u (calculated nuclear mass without electrons)Mass excess:27.59085 MeVMass defect:0.306058148 u (per nucleus)Nuclear binding energy:285.09132851 MeV (per nucleus)
7.12728321 MeV (average binding energy per nucleon)Separation energy:S_N = 1.13(56) MeV (first neutron)
S_P = 21.97(65) MeV (first proton)Half-life:260 nsDecay constant λ:2665950.6944613 s^-1Specific activity α:4.013682651923 × 10⁺²⁸ Bq g^-1
1.084779095114 × 10⁺¹⁸ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2002

Radioactive Decay

Half-life T_½ = 260 ns respectively 2.60 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	⁴⁰Si	100 %	22.16(53) MeV
β^-, n	³⁹Si	?	17.20(42) MeV
β^-, 2n	³⁸Si	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 27) and isobaric (same nucleon number A = 40) with Aluminium-40. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 27	Isobar A = 40
11	³⁸Na
12	³⁹Mg	⁴⁰Mg
13	⁴⁰Al	⁴⁰Al
14	⁴¹Si	⁴⁰Si
15	⁴²P	⁴⁰P
16	⁴³S	⁴⁰S
17	⁴⁴Cl	⁴⁰Cl
18	⁴⁵Ar	⁴⁰Ar
19	⁴⁶K	⁴⁰K
20	⁴⁷Ca	⁴⁰Ca
21	⁴⁸Sc	⁴⁰Sc
22	⁴⁹Ti	⁴⁰Ti
23	⁵⁰V	⁴⁰V
24	⁵¹Cr
25	⁵²Mn
26	⁵³Fe
27	⁵⁴Co
28	⁵⁵Ni
29	⁵⁶Cu
30	⁵⁷Zn
31	⁵⁸Ga
32	⁵⁹Ge