Arsenic-65

Properties and data of the isotope ⁶⁵As.

Content

General data

Name of the isotope:Arsenic-65; As-65Symbol:⁶⁵As or 6533AsMass number A:65 (= number of nucleons)Atomic number Z:33 (= number of protons)Neutrons N:32Isotopic mass:64.94961(9) u (atomic weight of Arsenic-65)Nuclide mass:64.9315075 u (calculated nuclear mass without electrons)Mass excess:-46.93798 MeVMass defect:0.585893368 u (per nucleus)Nuclear binding energy:545.75615693 MeV (per nucleus)
8.39624857 MeV (average binding energy per nucleon)Separation energy:S_N = 15.48(22) MeV (first neutron)Half-life:128(16) msDecay constant λ:5.4152123481246 s^-1Specific activity α:5.095495554199 × 10⁺²² Bq g^-1
1377160960594.4 Ci g^-1Spin and parity:
(nuclear angular momentum)3/2-Mirror nucleus:Germanium-65Year of discovery:1991

Radioactive Decay

Half-life T_½ = 128(16) ms respectively 1.28 × 10^-1 seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EE/β⁺	⁶⁵Ge	100 %	9.54(8) MeV

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 32) and isobaric (same nucleon number A = 65) with Arsenic-65. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

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