Gallium-73

Main isotopes of gallium

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)	69.723(1)

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.

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.

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