Aluminium-42

Properties and data of the isotope ⁴²Al.

Content

General data

Name of the isotope:Aluminium-42; Al-42Symbol:⁴²Al or 4213AlMass number A:42 (= number of nucleons)Atomic number Z:13 (= number of protons)Neutrons N:29Isotopic mass:42.04305(64) u (atomic weight of Aluminium-42)Nuclide mass:42.0359185 u (calculated nuclear mass without electrons)Mass excess:40.10082 MeVMass defect:0.30995798 u (per nucleus)Nuclear binding energy:288.72399862 MeV (per nucleus)
6.87438092 MeV (average binding energy per nucleon)Separation energy:S_N = 1.39(78) MeV (first neutron)Half-life:170 nsDecay constant λ:4077336.356235 s^-1Specific activity α:5.846260445378 × 10⁺²⁸ Bq g^-1
1.580070390642 × 10⁺¹⁸ Ci g^-1Spin and parity:
(nuclear angular momentum)Year of discovery:2007

Radioactive Decay

Half-life T_½ = 170 ns respectively 1.70 × 10^-7 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	⁴²Si	?	23.663(78) MeV
β^-, n	⁴¹Si	?	19.91(82) MeV
β^-, 2n	⁴⁰Si	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 29) and isobaric (same nucleon number A = 42) with Aluminium-42. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 29	Isobar A = 42
13	⁴²Al	⁴²Al
14	⁴³Si	⁴²Si
15	⁴⁴P	⁴²P
16	⁴⁵S	⁴²S
17	⁴⁶Cl	⁴²Cl
18	⁴⁷Ar	⁴²Ar
19	⁴⁸K	⁴²K
20	⁴⁹Ca	⁴²Ca
21	⁵⁰Sc	⁴²Sc
22	⁵¹Ti	⁴²Ti
23	⁵²V	⁴²V
24	⁵³Cr	⁴²Cr
25	⁵⁴Mn	⁴²Mn
26	⁵⁵Fe
27	⁵⁶Co
28	⁵⁷Ni
29	⁵⁸Cu
30	⁵⁹Zn
31	⁶⁰Ga
32	⁶¹Ge
33	⁶²As
34	⁶³Se