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Natural gallium (31Ga) consists of a mixture of two stable isotopes: gallium-69 and gallium-71. The most commercially important radioisotopes are gallium-67 and gallium-68.

Main isotopes of gallium (31Ga)
Iso­tope Decay
abun­dance half-life (t1/2) mode pro­duct
66Ga syn 9.5 h β+ 66Zn
67Ga syn 3.3 d ε 67Zn
68Ga syn 1.2 h β+ 68Zn
69Ga 60.11% stable
70Ga syn 21 min β 70Ge
ε 70Zn
71Ga 39.89% stable
72Ga syn 14.1 h β 72Ge
73Ga syn 4.9 h β 73Ge
Standard atomic weight Ar, standard(Ga)

Gallium-67 (half-life 3.3 days) is a gamma-emitting isotope (the gamma emitted immediately after electron-capture) used in standard nuclear medical imaging, in procedures usually referred to as gallium scans. It is usually used as the free ion, Ga3+. It is the longest-lived radioisotope of gallium.

The shorter-lived gallium-68 (half-life 68 minutes) is a positron-emitting isotope generated from germanium-68 in gallium-68 generators, for use in a small minority of diagnostic PET scans. For this use, it is usually attached as a tracer to a carrier molecule, which gives the resulting radiopharmaceutical a different tissue-uptake specificity from the ionic Ga-67 radioisotope normally used in standard gallium scans.

List of isotopesEdit

Nuclide
[n 1]
Z N Isotopic mass (u)
[n 2][n 3]
Half-life
Decay
mode

[n 4]
Daughter
isotope

[n 5]
Spin and
parity
[n 6][n 7]
Natural abundance (mole fraction)
Excitation energy Normal proportion Range of variation
56Ga 31 25 55.99491(28)# p 55Zn 3+#
57Ga 31 26 56.98293(28)# p 56Zn 1/2−#
58Ga 31 27 57.97425(23)# p 57Zn 2+#
59Ga 31 28 58.96337(18)# p 58Zn 3/2−#
60Ga 31 29 59.95706(12)# 70(10) ms β+ 60Zn (2+)
61Ga 31 30 60.94945(6) 168(3) ms β+ 61Zn 3/2−
62Ga 31 31 61.944175(30) 116.18(4) ms β+ 62Zn 0+
63Ga 31 32 62.9392942(14) 32.4(5) s β+ 63Zn (3/2−)
64Ga 31 33 63.9368387(22) 2.627(12) min β+ 64Zn 0(+#)
64mGa 42.85(8) keV 21.9(7) µs 2+
65Ga 31 34 64.9327348(9) 15.2(2) min β+ 65Zn 3/2−
66Ga 31 35 65.931589(3) 9.49(7) h β+ 66Zn 0+
67Ga[n 8] 31 36 66.9282017(14) 3.2612(6) d EC 67Zn 3/2−
68Ga[n 9] 31 37 67.9279801(16) 67.71(9) min β+ 68Zn 1+
69Ga 31 38 68.9255736(13) Stable 3/2− 0.60108(9)
70Ga 31 39 69.9260220(13) 21.14(3) min β (99.59) 70Ge 1+
EC (0.41%) 70Zn
71Ga 31 40 70.9247013(11) Stable 3/2− 0.39892(9)
72Ga 31 41 71.9263663(11) 14.095(3) h β 72Ge 3-
72mGa 119.66(5) keV 39.68(13) ms IT 72Ga (0+)
73Ga 31 42 72.9251747(18) 4.86(3) h β 73Ge 3/2−
74Ga 31 43 73.926946(4) 8.12(12) min β 74Ge (3-)
74mGa 59.571(14) keV 9.5(10) s (0)
75Ga 31 44 74.9265002(26) 126(2) s β 75Ge (3/2)−
76Ga 31 45 75.9288276(21) 32.6(6) s β 76Ge (2+,3+)
77Ga 31 46 76.9291543(26) 13.2(2) s β 77Ge (3/2−)
78Ga 31 47 77.9316082(26) 5.09(5) s β 78Ge (3+)
79Ga 31 48 78.93289(11) 2.847(3) s β (99.911%) 79mGe (3/2−)#
β, n (.089%) 78Ge
80Ga 31 49 79.93652(13) 1.697(11) s β (99.11%) 80Ge (3)
β, n (.89%) 79Ge
81Ga 31 50 80.93775(21) 1.217(5) s β (88.11%) 81mGe (5/2−)
β, n (11.89%) 80Ge
82Ga 31 51 81.94299(32)# 0.599(2) s β (78.5%) 82Ge (1,2,3)
β, n (21.5%) 81Ge
83Ga 31 52 82.94698(32)# 308(1) ms β (60%) 83Ge 3/2−#
β, n (40%) 82Ge
84Ga 31 53 83.95265(43)# 0.085(10) s β, n (70%) 83Ge
β (30%) 84Ge
85Ga 31 54 84.95700(54)# 50# ms [>300 ns] 3/2−#
86Ga 31 55 85.96312(86)# 30# ms [>300 ns]
  1. ^ mGa – Excited nuclear isomer.
  2. ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
  3. ^ # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
  4. ^ Modes of decay:
    EC: Electron capture
    IT: Isomeric transition
    n: Neutron emission
    p: Proton emission
  5. ^ Bold symbol as daughter – Daughter product is stable.
  6. ^ ( ) spin value – Indicates spin with weak assignment arguments.
  7. ^ # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
  8. ^ Deexcitation gamma used in medical imaging
  9. ^ Medically useful radioisotope
  • Commercially available materials may have been subjected to an undisclosed or inadvertent isotopic fractionation. Substantial deviations from the given mass and composition can occur.[original research?]

ReferencesEdit

  1. ^ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.