Argon-50

Properties and data of the isotope ⁵⁰Ar.

Content

General data

Name of the isotope:Argon-50; Ar-50Symbol:⁵⁰Ar or 5018ArMass number A:50 (= number of nucleons)Atomic number Z:18 (= number of protons)Neutrons N:32Isotopic mass:49.98569(54) u (atomic weight of Argon-50)Nuclide mass:49.9758157 u (calculated nuclear mass without electrons)Mass excess:-13.32968 MeVMass defect:0.432437888 u (per nucleus)Nuclear binding energy:402.81329804 MeV (per nucleus)
8.05626596 MeV (average binding energy per nucleon)Separation energy:S_N = 4.21(64) MeV (first neutron)
S_P = 21.56(78) MeV (first proton)Half-life:106(6) msDecay constant λ:6.5391243449051 s^-1Specific activity α:8.03663834809 × 10⁺²² Bq g^-1
2172064418403.8 Ci g^-1Spin and parity:
(nuclear angular momentum)0+Year of discovery:1989

Radioactive Decay

Half-life T_½ = 106(6) ms respectively 1.06 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy
β^-	⁵⁰K	65 %	12.40(50) MeV
β^-, n	⁴⁹K	35(7) %	8.21(50) MeV
β^-, 2n	⁴⁸K	?

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 32) and isobaric (same nucleon number A = 50) with Argon-50. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

OZ	Isotone N = 32	Isobar A = 50
16	⁴⁸S
17	⁴⁹Cl	⁵⁰Cl
18	⁵⁰Ar	⁵⁰Ar
19	⁵¹K	⁵⁰K
20	⁵²Ca	⁵⁰Ca
21	⁵³Sc	⁵⁰Sc
22	⁵⁴Ti	⁵⁰Ti
23	⁵⁵V	⁵⁰V
24	⁵⁶Cr	⁵⁰Cr
25	⁵⁷Mn	⁵⁰Mn
26	⁵⁸Fe	⁵⁰Fe
27	⁵⁹Co	⁵⁰Co
28	⁶⁰Ni	⁵⁰Ni
29	⁶¹Cu
30	⁶²Zn
31	⁶³Ga
32	⁶⁴Ge
33	⁶⁵As
34	⁶⁶Se
35	⁶⁷Br
36	⁶⁸Kr