Arsenic-71

Properties and data of the isotope ⁷¹As.

Contents

General data

Name of the isotope:Arsenic-71; As-71Symbol:⁷¹As or 7133AsMass number A:71 (= number of nucleons)Atomic number Z:33 (= number of protons)Neutrons N:38Isotopic mass:70.927114(4) u (atomic weight of Arsenic-71)Nuclide mass:70.9090115 u (calculated nuclear mass without electrons)Mass excess:-67.89287 MeVMass defect:0.66037886399999 u (per nucleus)Nuclear binding energy:615.13894954 MeV (per nucleus)
8.66392887 MeV (average binding energy per nucleon)Separation energy:S_N = 11.62(50) MeV (first neutron)
S_P = 4.62(4) MeV (first proton)Half-life:65.30(7) hDecay constant λ:2.94855870580 × 10^-6 s^-1Specific activity α:2.536662265733 × 10⁺¹⁶ Bq g^-1
685584.39614411 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2-Magnetic dipole moment:μ(μ_N) = +1.673(2)Quadrupole moment Q:- 0.021(6) barn (100 fm²)Nuclear g-factor:g_l = 0.6692Year of discovery:1939

Radioactive Decay

Half-life T_½ = 65.30(7) h (hours) respectively 2.35080 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁷¹Ge	100 %	2.013(4) MeV

Parent Nuclides

Direct parent isotope is: ⁷¹Se.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 38) and isobaric (same nucleon number A = 71) with Arsenic-71. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 38	Isobar A = 71
20	⁵⁸Ca
21	⁵⁹Sc
22	⁶⁰Ti
23	⁶¹V
24	⁶²Cr
25	⁶³Mn	⁷¹Mn
26	⁶⁴Fe	⁷¹Fe
27	⁶⁵Co	⁷¹Co
28	⁶⁶Ni	⁷¹Ni
29	⁶⁷Cu	⁷¹Cu
30	⁶⁸Zn	⁷¹Zn
31	⁶⁹Ga	⁷¹Ga
32	⁷⁰Ge	⁷¹Ge
33	⁷¹As	⁷¹As
34	⁷²Se	⁷¹Se
35	⁷³Br	⁷¹Br
36	⁷⁴Kr	⁷¹Kr
37	⁷⁵Rb	⁷¹Rb
38	⁷⁶Sr
39	⁷⁷Y
40	⁷⁸Zr