Germanium-69

Properties and data of the isotope ⁶⁹Ge.

Contents

General Data

Radioactive Decay

Parent Nuclides

Isotones und Isobares

Literature

Germanium-69 is a radioisotope of the chemical element germanium, which has 37 neutrons in its atomic nucleus in addition to the element-specific 32 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 ⁶⁹Ge is exclusively for academic purposes. However, there have recently been studies into the suitability of germanium-69 as a medical radionuclide - especially for PET imaging.

General data

Name of the isotope:Germanium-69; Ge-69Symbol:⁶⁹Ge or 6932GeMass number A:69 (= number of nucleons)Atomic number Z:32 (= number of protons)Neutrons N:37Isotopic mass:68.9279645(14) u (atomic weight of Germanium-69)Nuclide mass:68.9104105 u (calculated nuclear mass without electrons)Mass excess:-67.10064 MeVMass defect:0.643038416 u (per nucleus)Nuclear binding energy:598.98642627 MeV (per nucleus)
8.6809627 MeV (average binding energy per nucleon)Separation energy:S_N = 8.1932(23) MeV (first neutron)
S_P = 7.3036(19) MeV (first proton)Half-life:39.05(10) hDecay constant λ:4.930624417128 × 10^-6 s^-1Specific activity α:4.366605112851 × 10⁺¹⁶ Bq g^-1
1180163.544014 Ci g^-1Spin and parity:
(nuclear angular momentum)5/2-Magnetic dipole moment:μ(μ_N) = 0.735(7)Quadrupole moment Q:0.024(5) barn (100 fm²)Nuclear g-factor:g_l = 0.294Year of discovery:1938

Radioactive Decay

Half-life T_½ = 39.05(10) h (hours) respectively 1.40580 × 10⁵ seconds s.

Decay mode	Daughter	Probability	Decay energy	γ energy (intensity)
EC/β⁺	⁶⁹Ga	100 %	2.2271(18) MeV

Formation and radioactive decay of germanium-69

Parent Nuclides

Direct parent isotope is: ⁶⁹As.

Nuclear Isomers

Nuclear isomers or excited states with the activation energy in keV related to the ground state.

Nuclear Isomer	Excitation Energy	Half-life	Spin
^69m1Ge	86.76(2) keV	5.1(2) μs	1/2-
^69m2Ge	397.94(2) keV	2.81(5) μs	9/2+

Isotones and Isobars

The following table shows the atomic nuclei that are isotonic (same neutron number N = 37) and isobaric (same nucleon number A = 69) with Germanium-69. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.

Z	Isotone N = 37	Isobar A = 69
19	⁵⁶K
20	⁵⁷Ca
21	⁵⁸Sc
22	⁵⁹Ti
23	⁶⁰V
24	⁶¹Cr
25	⁶²Mn	⁶⁹Mn
26	⁶³Fe	⁶⁹Fe
27	⁶⁴Co	⁶⁹Co
28	⁶⁵Ni	⁶⁹Ni
29	⁶⁶Cu	⁶⁹Cu
30	⁶⁷Zn	⁶⁹Zn
31	⁶⁸Ga	⁶⁹Ga
32	⁶⁹Ge	⁶⁹Ge
33	⁷⁰As	⁶⁹As
34	⁷¹Se	⁶⁹Se
35	⁷²Br	⁶⁹Br
36	⁷³Kr	⁶⁹Kr
37	⁷⁴Rb
38	⁷⁵Sr
39	⁷⁶Y
40	⁷⁷Zr