Isotopes of gallium

Natural gallium (Ga) 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.

Relative atomic mass: 69.723(1)

Table

nuclide symbol	Z(p)	N(n)	isotopic mass (u)	half-life	decay mode(s)[1][n 1]	daughter isotope(s)[n 2]	nuclear spin	representative isotopic composition (mole fraction)	range of natural variation (mole fraction)
	excitation energy
^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 3]	31	36	66.9282017(14)	3.2612(6) d	EC	^67Zn	3/2−
^68Ga[n 4]	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. Abbreviations:
   EC: Electron capture
   IT: Isomeric transition
2. Bold for stable isotopes, bold italics for nearly stable isotopes (half-life longer than the age of the universe)
3. Deexcitation gamma used in medical imaging
4. Medically useful radioisotope

Notes

• Commercially available materials may have been subjected to an undisclosed or inadvertent isotopic fractionation. Substantial deviations from the given mass and composition can occur.
• Values marked # are not purely derived from experimental data, but at least partly from systematic trends. Spins with weak assignment arguments are enclosed in parentheses.
• Uncertainties are given in concise form in parentheses after the corresponding last digits. Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC, which use expanded uncertainties.
• Nuclide masses are given by IUPAP Commission on Symbols, Units, Nomenclature, Atomic Masses and Fundamental Constants (SUNAMCO).
• Isotope abundances are given by IUPAC Commission on Isotopic Abundances and Atomic Weights.

References

1. "Universal Nuclide Chart". nucleonica. (registration required (help)).

• Isotope masses from:
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
• Isotopic compositions and standard atomic masses from:
  • J. R. de Laeter; J. K. Böhlke; P. De Bièvre; H. Hidaka; H. S. Peiser; K. J. R. Rosman; P. D. P. Taylor (2003). "Atomic weights of the elements. Review 2000 (IUPAC Technical Report)". Pure and Applied Chemistry 75 (6): 683–800. doi:10.1351/pac200375060683.
  • M. E. Wieser (2006). "Atomic weights of the elements 2005 (IUPAC Technical Report)". Pure and Applied Chemistry 78 (11): 2051–2066. doi:10.1351/pac200678112051. Lay summary.
• Half-life, spin, and isomer data selected from the following sources. See editing notes on this article's talk page.
  • G. Audi; A. H. Wapstra; C. Thibault; J. Blachot; O. Bersillon (2003). "The NUBASE evaluation of nuclear and decay properties" (PDF). Nuclear Physics A 729: 3–128. Bibcode:2003NuPhA.729....3A. doi:10.1016/j.nuclphysa.2003.11.001.
  • National Nuclear Data Center. "NuDat 2.1 database". Brookhaven National Laboratory. Retrieved September 2005.
  • N. E. Holden (2004). "Table of the Isotopes". In D. R. Lide. CRC Handbook of Chemistry and Physics (85th ed.). CRC Press. Section 11. ISBN 978-0-8493-0485-9.