Argon-47

Properties and data of the isotope ⁴⁷Ar.

Content

General data

Name of the isotope:Argon-47; Ar-47Symbol:⁴⁷Ar or 4718ArMass number A:47 (= number of nucleons)Atomic number Z:18 (= number of protons)Neutrons N:29Isotopic mass:46.9727681(12) u (atomic weight of Argon-47)Nuclide mass:46.9628938 u (calculated nuclear mass without electrons)Mass excess:-25.36635 MeVMass defect:0.41936504 u (per nucleus)Nuclear binding energy:390.63601857 MeV (per nucleus)
8.31140465 MeV (average binding energy per nucleon)Separation energy:S_N = 3.6647(16) MeV (first neutron)
S_P = 18.80(21) MeV (first proton)Half-life:1.23(3) sDecay constant λ:0.56353429313817 s^-1Specific activity α:7.377571505832 × 10⁺²¹ Bq g^-1
199393824481.96 Ci g^-1Spin and parity:
(nuclear angular momentum)(3/2)-Year of discovery:1985

Radioactive Decay

Half-life T_½ = 1.23(3) s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
β^-	⁴⁷K	> 99.8 %	10.3456(18) MeV
β^-, n	⁴⁶K	< 0.2 %	1.9763(13) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 29) and isobaric (same nucleon number A = 47) with Argon-47. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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