Argon-46

Properties and data of the isotope ⁴⁶Ar.

Content

General data

Name of the isotope:Argon-46; Ar-46Symbol:⁴⁶Ar or 4618ArMass number A:46 (= number of nucleons)Atomic number Z:18 (= number of protons)Neutrons N:28Isotopic mass:45.9680374(12) u (atomic weight of Argon-46)Nuclide mass:45.9581631 u (calculated nuclear mass without electrons)Mass excess:-29.77297 MeVMass defect:0.415430824 u (per nucleus)Nuclear binding energy:386.97131997 MeV (per nucleus)
8.41242 MeV (average binding energy per nucleon)Separation energy:S_N = 8.0734(12) MeV (first neutron)
S_P = 18.80(14) MeV (first proton)Half-life:8.4(6) sDecay constant λ:0.082517521495232 s^-1Specific activity α:1.104293639682 × 10⁺²¹ Bq g^-1
29845774045.473 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Charge radius:3.4377(44) femtometer fmYear of discovery:1974

Radioactive Decay

Half-life T_½ = 8.4(6) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁴⁶K	100 %	5.6410(13) MeV

Parent Nuclides

Direct parent isotope is: ⁴⁶Cl.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 28) and isobaric (same nucleon number A = 46) with Argon-46. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 28	Isobar A = 46
11	³⁹Na
12	⁴⁰Mg
13	⁴¹Al
14	⁴²Si
15	⁴³P	⁴⁶P
16	⁴⁴S	⁴⁶S
17	⁴⁵Cl	⁴⁶Cl
18	⁴⁶Ar	⁴⁶Ar
19	⁴⁷K	⁴⁶K
20	⁴⁸Ca	⁴⁶Ca
21	⁴⁹Sc	⁴⁶Sc
22	⁵⁰Ti	⁴⁶Ti
23	⁵¹V	⁴⁶V
24	⁵²Cr	⁴⁶Cr
25	⁵³Mn	⁴⁶Mn
26	⁵⁴Fe	⁴⁶Fe
27	⁵⁵Co	⁴⁶Co
28	⁵⁶Ni
29	⁵⁷Cu
30	⁵⁸Zn
31	⁵⁹Ga
32	⁶⁰Ge