Isotopes of germanium

Germanium (₃₂Ge) has five naturally occurring isotopes, ⁷⁰Ge, ⁷²Ge, ⁷³Ge, ⁷⁴Ge, and ⁷⁶Ge. Of these, ⁷⁶Ge is very slightly radioactive, undergoing double beta decay with a half-life of 2.02 ÃƒÂ— 10²¹ years (over 100 billion times the age of the universe).

Stable ⁷⁴Ge is the most common isotope, having a natural abundance of 36.52%; ⁷⁶Ge is the least common with a natural abundance of 7.75%.

At least 27 additional radioisotopes have also been synthesized ranging in atomic mass from 58 to 89. The most stable of these is ⁶⁸Ge, decaying by electron capture with a half-life of 271.05 days, whose daughter is the medically useful positron-emitting isotope ⁶⁸Ga. (See gallium-68 generator for notes on the source of this isotope, and its medical use.) The next after that is ⁷¹Ge, also decaying by electron capture with half-life 11.468 days, and the rest are all less than two days, most under two hours.

While most of germanium's radioisotopes decay by beta decay - β⁺ for isotopes lighter than 74-76, and β^- for those heavier - isotopes as heavy as ⁶⁵Ge can also decay by β⁺-delayed proton emission, and those as light as ⁸⁴Ge by β^−-delayed neutron emission.

⁷⁶Ge is used in experiments on the nature of neutrinos, by searching for neutrinoless double beta decay.

List of isotopes

|-id=Germanium-59 | rowspan=3|⁵⁹Ge | rowspan=3 style="text-align:right" | 32 | rowspan=3 style="text-align:right" | 27 | rowspan=3|58.98243(43)# | rowspan=3|13.3(17)&nbsp;ms | β⁺, p (93%) | ⁵⁸Zn | rowspan=3|7/2−# | rowspan=3| | rowspan=3| |- | β⁺ (7%) | ⁵⁹Ga |- | 2p (<0.2%) | ⁵⁷Zn |-id=Germanium-60 | rowspan=2|⁶⁰Ge | rowspan=2 style="text-align:right" | 32 | rowspan=2 style="text-align:right" | 28 | rowspan=2|59.970286(24) | rowspan=2|25.0(3)&nbsp;ms | β⁺, p (67%) | ⁵⁹Zn | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β⁺ (33%) | ⁶⁰Ga |-id=Germanium-61 | rowspan=2|⁶¹Ge | rowspan=2 style="text-align:right" | 32 | rowspan=2 style="text-align:right" | 29 | rowspan=2|60.96373(32)# | rowspan=2|40.7(4)&nbsp;ms | β⁺, p (87%) | ⁶⁰Zn | rowspan=2|3/2−# | rowspan=2| | rowspan=2| |- | β⁺ (13%) | ⁶¹Ga |-id=Germanium-62 | ⁶²Ge | style="text-align:right" | 32 | style="text-align:right" | 30 | 61.95463(15) | 73.5(1)&nbsp;ms | β⁺ | ⁶²Ga | 0+ | | |-id=Germanium-63 | ⁶³Ge | style="text-align:right" | 32 | style="text-align:right" | 31 | 62.949628(40) | 153.6(11)&nbsp;ms | β⁺ | ⁶³Ga | 3/2−# | | |-id=Germanium-64 | ⁶⁴Ge | style="text-align:right" | 32 | style="text-align:right" | 32 | 63.9416899(40) | 63.7(25)&nbsp;s | β⁺ | ⁶⁴Ga | 0+ | | |-id=Germanium-65 | rowspan=2|⁶⁵Ge | rowspan=2 style="text-align:right" | 32 | rowspan=2 style="text-align:right" | 33 | rowspan=2|64.9393681(23) | rowspan=2|30.9(5)&nbsp;s | β⁺ (99.99%) | ⁶⁵Ga | rowspan=2|3/2− | rowspan=2| | rowspan=2| |- | β⁺, p (0.011%) | ⁶⁴Zn |-id=Germanium-66 | ⁶⁶Ge | style="text-align:right" | 32 | style="text-align:right" | 34 | 65.9338621(26) | 2.26(5)&nbsp;h | β⁺ | ⁶⁶Ga | 0+ | | |-id=Germanium-67 | ⁶⁷Ge | style="text-align:right" | 32 | style="text-align:right" | 35 | 66.9327170(46) | 18.9(3)&nbsp;min | β⁺ | ⁶⁷Ga | 1/2− | | |-id=Germanium-67m1 | style="text-indent:1em" | ^67m1Ge | colspan="3" style="text-indent:2em" | 18.20(5)&nbsp;keV | 13.7(9)&nbsp;μs | IT | ⁶⁷Ge | 5/2− | | |-id=Germanium-67m2 | style="text-indent:1em" | ^67m2Ge | colspan="3" style="text-indent:2em" | 751.70(6)&nbsp;keV | 109.1(38)&nbsp;ns | IT | ⁶⁷Ge | 9/2+ | | |-id=Germanium-68 | ⁶⁸Ge | style="text-align:right" | 32 | style="text-align:right" | 36 | 67.9280953(20) | 271.05(8)&nbsp;d | EC | ⁶⁸Ga | 0+ | | |-id=Germanium-69 | ⁶⁹Ge | style="text-align:right" | 32 | style="text-align:right" | 37 | 68.9279645(14) | 39.05(10)&nbsp;h | β⁺ | ⁶⁹Ga | 5/2− | | |-id=Germanium-69m1 | style="text-indent:1em" | ^69m1Ge | colspan="3" style="text-indent:2em" | 86.76(2)&nbsp;keV | 5.1(2)&nbsp;μs | IT | ⁶⁹Ge | 1/2− | | |-id=Germanium-69m2 | style="text-indent:1em" | ^69m2Ge | colspan="3" style="text-indent:2em" | 397.94(2)&nbsp;keV | 2.81(5)&nbsp;μs | IT | ⁶⁹Ge | 9/2+ | | |-id=Germanium-70 | ⁷⁰Ge | style="text-align:right" | 32 | style="text-align:right" | 38 | 69.92424854(88) | colspan=3 align=center|Stable | 0+ | 0.2052(19) | |-id=Germanium-71 | ⁷¹Ge | style="text-align:right" | 32 | style="text-align:right" | 39 | 70.92495212(87) | 11.468(8)&nbsp;d | EC | ⁷¹Ga | 1/2− | | |-id=Germanium-71m | style="text-indent:1em" | ^71mGe | colspan="3" style="text-indent:2em" | 198.354(14)&nbsp;keV | 20.41(18)&nbsp;ms | IT | ⁷¹Ge | 9/2+ | | |-id=Germanium-72 | ⁷²Ge | style="text-align:right" | 32 | style="text-align:right" | 40 | 71.922075824(81) | colspan=3 align=center|Stable | 0+ | 0.2745(15) | |-id=Germanium-72m | style="text-indent:1em" | ^72mGe | colspan="3" style="text-indent:2em" | 691.43(4)&nbsp;keV | 444.2(8)&nbsp;ns | IT | ⁷²Ge | 0+ | | |-id=Germanium-73 | ⁷³Ge | style="text-align:right" | 32 | style="text-align:right" | 41 | 72.923458954(61) | colspan=3 align=center|Stable | 9/2+ | 0.0776(8) | |-id=Germanium-73m1 | style="text-indent:1em" | ^73m1Ge | colspan="3" style="text-indent:2em" | 13.2845(15)&nbsp;keV | 2.91(3)&nbsp;μs | IT | ⁷³Ge | 5/2+ | | |-id=Germanium-73m2 | style="text-indent:1em" | ^73m2Ge | colspan="3" style="text-indent:2em" | 66.725(9)&nbsp;keV | 499(11)&nbsp;ms | IT | ⁷³Ge | 1/2− | | |-id=Germanium-74 | ⁷⁴Ge | style="text-align:right" | 32 | style="text-align:right" | 42 | 73.921177760(13) | colspan=3 align=center|Stable | 0+ | 0.3652(12) | |-id=Germanium-75 | ⁷⁵Ge | style="text-align:right" | 32 | style="text-align:right" | 43 | 74.922858370(55) | 82.78(4)&nbsp;min | β^− | ⁷⁵As | 1/2− | | |-id=Germanium-75m1 | rowspan=2 style="text-indent:1em" | ^75m1Ge | rowspan=2 colspan="3" style="text-indent:2em" | 139.69(3)&nbsp;keV | rowspan=2|47.7(5)&nbsp;s | IT (99.97%) | ⁷⁵Ge | rowspan=2|7/2+ | rowspan=2| | rowspan=2| |- | β^− (0.030%) | ⁷⁵As |-id=Germanium-75m2 | style="text-indent:1em" | ^75m2Ge | colspan="3" style="text-indent:2em" | 192.19(6)&nbsp;keV | 216(5)&nbsp;ns | IT | ⁷⁵Ge | 5/2+ | | |-id=Germanium-76 | ⁷⁶Ge | style="text-align:right" | 32 | style="text-align:right" | 44 | 75.921402725(19) | (2.022±0.018±0.038) y | β^−β^− | ⁷⁶Se | 0+ | 0.0775(12) | |-id=Germanium-77 | ⁷⁷Ge | style="text-align:right" | 32 | style="text-align:right" | 45 | 76.923549843(56) | 11.211(3)&nbsp;h | β^− | ⁷⁷As | 7/2+ | | |-id=Germanium-77m | rowspan=2 style="text-indent:1em" | ^77mGe | rowspan=2 colspan="3" style="text-indent:2em" | 159.71(6)&nbsp;keV | rowspan=2|53.7(6)&nbsp;s | β^− (81%) | ⁷⁷As | rowspan=2|1/2− | rowspan=2| | rowspan=2| |- | IT (19%) | ⁷⁷Ge |-id=Germanium-78 | ⁷⁸Ge | style="text-align:right" | 32 | style="text-align:right" | 46 | 77.9228529(38) | 88.0(10)&nbsp;min | β^− | ⁷⁸As | 0+ | | |-id=Germanium-79 | ⁷⁹Ge | style="text-align:right" | 32 | style="text-align:right" | 47 | 78.925360(40) | 18.98(3)&nbsp;s | β^− | ⁷⁹As | (1/2)− | | |-id=Germanium-79m | rowspan=2 style="text-indent:1em" | ^79mGe | rowspan=2 colspan="3" style="text-indent:2em" | 185.95(4)&nbsp;keV | rowspan=2|39.0(10)&nbsp;s | β^− (96%) | ⁷⁹As | rowspan=2|7/2+# | rowspan=2| | rowspan=2| |- | IT (4%) | ⁷⁹Ge |-id=Germanium-80 | ⁸⁰Ge | style="text-align:right" | 32 | style="text-align:right" | 48 | 79.9253508(22) | 29.5(4)&nbsp;s | β^− | ⁸⁰As | 0+ | | |-id=Germanium-81 | ⁸¹Ge | style="text-align:right" | 32 | style="text-align:right" | 49 | 80.9288329(22) | 9(2)&nbsp;s | β^− | ⁸¹As | 9/2+# | | |-id=Germanium-81m | rowspan=2 style="text-indent:1em" | ^81mGe | rowspan=2 colspan="3" style="text-indent:2em" | 679.14(4)&nbsp;keV | rowspan=2|6(2)&nbsp;s | β^− | ⁸¹As | rowspan=2|(1/2+) | rowspan=2| | rowspan=2| |- | IT (<1%) | ⁸¹Ge |-id=Germanium-82 | ⁸²Ge | style="text-align:right" | 32 | style="text-align:right" | 50 | 81.9297740(24) | 4.31(19)&nbsp;s | β^− | ⁸²As | 0+ | | |-id=Germanium-83 | ⁸³Ge | style="text-align:right" | 32 | style="text-align:right" | 51 | 82.9345391(26) | 1.85(6)&nbsp;s | β^− | ⁸³As | (5/2+) | | |-id=Germanium-84 | rowspan=2|⁸⁴Ge | rowspan=2 style="text-align:right" | 32 | rowspan=2 style="text-align:right" | 52 | rowspan=2|83.9375751(34) | rowspan=2|951(9)&nbsp;ms | β^− (89.4%) | ⁸⁴As | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β^−, n (10.6%) | ⁸³As |-id=Germanium-85 | rowspan=2|⁸⁵Ge | rowspan=2 style="text-align:right" | 32 | rowspan=2 style="text-align:right" | 53 | rowspan=2|84.9429697(40) | rowspan=2|495(5)&nbsp;ms | β^− (82.8%) | ⁸⁵As | rowspan=2|(3/2+,5/2+)# | rowspan=2| | rowspan=2| |- | β^−, n (17.2%) | ⁸⁴As |-id=Germanium-86 | rowspan=2|⁸⁶Ge | rowspan=2 style="text-align:right" | 32 | rowspan=2 style="text-align:right" | 54 | rowspan=2|85.94697(47) | rowspan=2|221.6(11)&nbsp;ms | β^− (55%) | ⁸⁶As | rowspan=2|0+ | rowspan=2| | rowspan=2| |- | β^−, n (45%) | ⁸⁵As |-id=Germanium-87 | ⁸⁷Ge | style="text-align:right" | 32 | style="text-align:right" | 55 | 86.95320(32)# | 103(4)&nbsp;ms | β^− | ⁸⁷As | 5/2+# | | |-id=Germanium-88 | ⁸⁸Ge | style="text-align:right" | 32 | style="text-align:right" | 56 | 87.95757(43)# | 61(6)&nbsp;ms | β^− | ⁸⁸As | 0+ | | |-id=Germanium-89 | ⁸⁹Ge | style="text-align:right" | 32 | style="text-align:right" | 57 | 88.96453(43)# | 60#&nbsp;ms [>300&nbsp;ns] | | | 3/2+# | | |-id=Germanium-90 | ⁹⁰Ge | style="text-align:right" | 32 | style="text-align:right" | 58 | 89.96944(54)# | 30#&nbsp;ms [>400&nbsp;ns] | | | 0+ | | |-id=Germanium-91 | ⁹¹Ge | style="text-align:right" | 32 | style="text-align:right" | 59 | | | | | | | |-id=Germanium-92 | ⁹²Ge | style="text-align:right" | 32 | style="text-align:right" | 60 | | | | | | |

See also

Daughter products other than germanium

• Isotopes of selenium
• Isotopes of arsenic
• Isotopes of gallium
• Isotopes of zinc
• Isotopes of copper

References