Arsenic-69

Properties and data of the isotope ⁶⁹As.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Arsenic-69 is a radioisotope of the chemical element arsenic, which has 36 neutrons in its atomic nucleus in addition to the element-specific 33 protons; the sum of the number of these atomic nucleus building blocks results in a mass number of 69. The very short-lived, only artificially produced, unstable and thus radioactive nuclide has no practical significance; the study of ⁶⁹As is exclusively for academic purposes.

The first reports on the radioactive isotope date back to 1955 [1]. The artificial production of the nuclide was achieved through the nuclear reactions

⁷⁰Ge(p,2n)⁶⁹As [1],

⁵⁹Co(¹²C,2n)⁶⁹As [2] and

⁴⁰Ca(³²S,3p)⁶⁹As [3].

See also: List of individual Arsenic isotopes (and general data sources).

General data

Name of the isotope:Arsenic-69; As-69Symbol:⁶⁹As or 6933AsMass number A:69 (= number of nucleons)Atomic number Z:33 (= number of protons)Neutrons N:36Nucleon pairing (Z - N):odd - evenNuclear ratio (N/Z ratio):1.0909090909091 (= neutron-proton ratio)Neutron excess (N-Z):3Isotopic mass:68.93225(3) u (atomic weight of Arsenic-69)Nuclide mass:68.9141475 u (calculated nuclear mass without electrons)Mass excess:-63.10872 MeVMass defect:0.63791303200001 u (per nucleus)Nuclear binding energy:594.21216183 MeV (per nucleus)
8.61177046 MeV (average binding energy per nucleon)Separation energy:S_N = 12.289(32) MeV (first neutron)
S_P = 3.422(32) MeV (first proton)Half-life:15.2(2) minDecay constant λ:0.00076002980324555 s^-1Specific activity α:6.639862266123 × 10⁺¹⁸ Bq g^-1
179455736.92225 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2-Magnetic dipole moment:μ(μ_N) = +1.622(2)Nuclear g-factor:g_l = 0.6488Mirror nucleus:Krypton-69Year of discovery:1955

Radioactive Decay

Half-life T_½ = 15.2(2) min (minutes) respectively 9.12 × 10² seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁶⁹Ge	100 %	3.988(32) MeV

Formation and radioactive decay of arsenic-69

Parent Nuclides

Direct parent isotope is: ⁶⁹Se.

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 36) and isobaric (same nucleon number A = 69) with Arsenic-69. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 36	Isobar A = 69
18	⁵⁴Ar
19	⁵⁵K
20	⁵⁶Ca
21	⁵⁷Sc
22	⁵⁸Ti
23	⁵⁹V
24	⁶⁰Cr
25	⁶¹Mn	⁶⁹Mn
26	⁶²Fe	⁶⁹Fe
27	⁶³Co	⁶⁹Co
28	⁶⁴Ni	⁶⁹Ni
29	⁶⁵Cu	⁶⁹Cu
30	⁶⁶Zn	⁶⁹Zn
31	⁶⁷Ga	⁶⁹Ga
32	⁶⁸Ge	⁶⁹Ge
33	⁶⁹As	⁶⁹As
34	⁷⁰Se	⁶⁹Se
35	⁷¹Br	⁶⁹Br
36	⁷²Kr	⁶⁹Kr
37	⁷³Rb
38	⁷⁴Sr

External data and identifiers

Adopted Levels, Gammas:NuDat 69As

Literature and References

[1] - F. D. S. Butement, E. G. Prout:
Radioactive ⁶⁹As and ⁷⁰As.
In: The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 46(374), (1955), DOI 10.1080/14786440308521089.

[2] - S. Muszynski, S. K. Mark:
The decay of ⁶⁹As.
In: Nuclear Physics A, 142(3), (1970), DOI 10.1016/0375-9474(70)90804-3.

[3] - M. Matejska-Minda et al.:
Lifetime Measurements of Short Lived States in ⁶⁹As.
In: Acta Physica Polonica B, 45, 235, (2014), DOI 10.5506/APhysPolB.45.235.