Copper (29Cu) has two stable isotopes, 63Cu and 65Cu, along with 28 radioisotopes. The most stable radioisotope is 67Cu with a half-life of 61.83 hours. Most of the others have half-lives under a minute. Unstable copper isotopes with atomic masses below 63 tend to undergo β+ decay, while isotopes with atomic masses above 65 tend to undergo β− decay. 64Cu decays by both β+ and β−.[1]
There are at least 10 metastable isomers of copper, including two each for 70Cu and 75Cu. The most stable of these is 68mCu with a half-life of 3.75 minutes. The least stable is 75m2Cu with a half-life of 149 ns.[1]
List of isotopes
Nuclide [n 1] |
Z | N | Isotopic mass (Da)[4] [n 2][n 3] |
Half-life[1] |
Decay mode[1] [n 4] |
Daughter isotope [n 5] |
Spin and parity[1] [n 6][n 7] |
Natural abundance (mole fraction) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Excitation energy[n 7] | Normal proportion[1] | Range of variation | |||||||||||||||||
55Cu | 29 | 26 | 54.96604(17) | 55.9(15) ms | β+ | 55Ni | 3/2−# | ||||||||||||
β+, p? | 54Co | ||||||||||||||||||
56Cu | 29 | 27 | 55.9585293(69) | 80.8(6) ms | β+ (99.60%) | 56Ni | (4+) | ||||||||||||
β+, p (0.40%) | 55Co | ||||||||||||||||||
57Cu | 29 | 28 | 56.94921169(54) | 196.4(7) ms | β+ | 57Ni | 3/2− | ||||||||||||
58Cu | 29 | 29 | 57.94453228(60) | 3.204(7) s | β+ | 58Ni | 1+ | ||||||||||||
59Cu | 29 | 30 | 58.93949671(57) | 81.5(5) s | β+ | 59Ni | 3/2− | ||||||||||||
60Cu | 29 | 31 | 59.9373638(17) | 23.7(4) min | β+ | 60Ni | 2+ | ||||||||||||
61Cu | 29 | 32 | 60.9334574(10) | 3.343(16) h | β+ | 61Ni | 3/2− | ||||||||||||
62Cu | 29 | 33 | 61.9325948(07) | 9.672(8) m | β+ | 62Ni | 1+ | ||||||||||||
63Cu | 29 | 34 | 62.92959712(46) | Stable | 3/2− | 0.6915(15) | |||||||||||||
64Cu | 29 | 35 | 63.92976400(46) | 12.7004(13) h | β+ (61.52%) | 64Ni | 1+ | ||||||||||||
β− (38.48%) | 64Zn | ||||||||||||||||||
65Cu | 29 | 36 | 64.92778948(69) | Stable | 3/2− | 0.3085(15) | |||||||||||||
66Cu | 29 | 37 | 65.92886880(70) | 5.120(14) min | β− | 66Zn | 1+ | ||||||||||||
66mCu | 1154.2(14) keV | 600(17) ns | IT | 68Cu | (6)− | ||||||||||||||
67Cu | 29 | 38 | 66.92772949(96) | 61.83(12) h | β− | 67Zn | 3/2− | ||||||||||||
68Cu | 29 | 39 | 67.9296109(17) | 30.9(6) s | β− | 68Zn | 1+ | ||||||||||||
68mCu | 721.26(8) keV | 3.75(5) min | IT (86%) | 68Cu | 6− | ||||||||||||||
β− (14%) | 68Zn | ||||||||||||||||||
69Cu | 29 | 40 | 68.929429267(15) | 2.85(15) min | β− | 69Zn | 3/2− | ||||||||||||
69mCu | 2742.0(7) keV | 357(2) ns | IT | 69Cu | (13/2+) | ||||||||||||||
70Cu | 29 | 41 | 69.9323921(12) | 44.5(2) s | β− | 70Zn | 6− | ||||||||||||
70m1Cu | 101.1(3) keV | 33(2) s | β− (52%) | 70Zn | 3− | ||||||||||||||
IT (48%) | 70Cu | ||||||||||||||||||
70m2Cu | 242.6(5) keV | 6.6(2) s | β− (93.2%) | 70Zn | 1+ | ||||||||||||||
IT (6.8%) | 70Cu | ||||||||||||||||||
71Cu | 29 | 42 | 70.9326768(16) | 19.4(14) s | β− | 71Zn | 3/2− | ||||||||||||
71mCu | 2755.7(6) keV | 271(13) ns | IT | 71Cu | (19/2−) | ||||||||||||||
72Cu | 29 | 43 | 71.9358203(15) | 6.63(3) s | β− | 72Zn | 2− | ||||||||||||
72mCu | 270(3) keV | 1.76(3) μs | IT | 72Cu | (6−) | ||||||||||||||
73Cu | 29 | 44 | 72.9366744(21) | 4.20(12) s | β− (99.71%) | 73Zn | 3/2− | ||||||||||||
β−, n (0.29%) | 72Zn | ||||||||||||||||||
74Cu | 29 | 45 | 73.9398749(66) | 1.606(9) s | β− (99.93%) | 74Zn | 2− | ||||||||||||
β−, n (0.075%) | 73Zn | ||||||||||||||||||
75Cu | 29 | 46 | 74.94152382(77) | 1.224(3) s | β− (97.3%) | 75Zn | 5/2− | ||||||||||||
β−, n (2.7%) | 74Zn | ||||||||||||||||||
75m1Cu | 61.7(4) keV | 0.310(8) μs | IT | 75Cu | 1/2− | ||||||||||||||
75m2Cu | 66.2(4) keV | 0.149(5) μs | IT | 75Cu | 3/2− | ||||||||||||||
76Cu | 29 | 47 | 75.94526897(98) | 637.7(55) ms | β− (92.8%) | 76Zn | 3− | ||||||||||||
β−, n (7.2%) | 75Zn | ||||||||||||||||||
77Cu | 29 | 48 | 76.9475436(13) | 470.3(17) ms | β− (69.9%) | 77Zn | 5/2− | ||||||||||||
β−, n (30.1%) | 76Zn | ||||||||||||||||||
78Cu | 29 | 49 | 77.951917(14) | 330.7(20) ms | β−, n (50.6%) | 77Zn | (6−) | ||||||||||||
β− (49.4%) | 78Zn | ||||||||||||||||||
β−, 2n? | 76Zn | ||||||||||||||||||
79Cu | 29 | 50 | 78.95447(11) | 241.3(21) ms | β−, n (66%) | 78Zn | (5/2−) | ||||||||||||
β− (34%) | 79Zn | ||||||||||||||||||
β−, 2n? | 77Zn | ||||||||||||||||||
80Cu | 29 | 51 | 79.96062(32)# | 113.3(64) ms | β−, n (59%) | 79Zn | |||||||||||||
β− (41%) | 80Zn | ||||||||||||||||||
β−, 2n? | 78Zn | ||||||||||||||||||
81Cu | 29 | 52 | 80.96574(32)# | 73.2(68) ms | β−, n (81%) | 80Zn | 5/2−# | ||||||||||||
β− (19%) | 81Zn | ||||||||||||||||||
β−, 2n? | 79Zn | ||||||||||||||||||
82Cu | 29 | 53 | 81.97238(43)# | 34(7) ms | β− | 82Zn | 5/2−# | ||||||||||||
β−, n? | 81Zn | ||||||||||||||||||
β−, 2n? | 80Zn | ||||||||||||||||||
83Cu | 29 | 54 | 82.97811(54)# | 21# ms [>410 ns] | β−? | 83Zn | 5/2−# | ||||||||||||
β−, n? | 82Zn | ||||||||||||||||||
β−, 2n? | 81Zn | ||||||||||||||||||
84Cu[5] | 29 | 55 | 83.98527(54)# | β−? | 84Zn | ||||||||||||||
β−, n? | 84Zn | ||||||||||||||||||
This table header & footer: |
- mCu – Excited nuclear isomer.
- ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- # – Atomic mass marked #: value and uncertainty derived not from purely experimental data, but at least partly from trends from the Mass Surface (TMS).
- Modes of decay:
IT: Isomeric transition n: Neutron emission p: Proton emission - Bold symbol as daughter – Daughter product is stable.
- ( ) spin value – Indicates spin with weak assignment arguments.
- # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
Copper nuclear magnetic resonance
Both stable isotopes of copper (63Cu and 65Cu) have nuclear spin of 3/2−, and thus produce nuclear magnetic resonance spectra, although the spectral lines are broad due to quadrupolar broadening. 63Cu is the more sensitive nucleus while 65Cu yields very slightly narrower signals. Usually though 63Cu NMR is preferred.[6]
Medical applications
Copper offers a relatively large number of radioisotopes that are potentially useful for nuclear medicine.
There is growing interest in the use of 64Cu, 62Cu, 61Cu, and 60Cu for diagnostic purposes and 67Cu and 64Cu for targeted radiotherapy. For example, 64Cu has a longer half-life than most positron-emitters (12.7 hours) and is thus ideal for diagnostic PET imaging of biological molecules.[7]