Naturally occurring cobalt (Co) consists of a single stable isotope, Co. Twenty-eight radioisotopes have been characterized; the most stable are Co with a half-life of 5.2714 years, Co (271.8 days), Co (77.27 days), and Co (70.86 days). All other isotopes have half-lives less than 18 hours and most of these have half-lives less than 1 second. This element also has 11 meta states, all of which have half-lives less than 15 minutes. The isotopes of cobalt range in atomic weight from Co to Co. The main

decay mode Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...

for isotopes with atomic mass less than that of the stable isotope, Co, is electron capture and the main mode of decay for those of greater than 59 atomic mass units is beta decay. The main

decay product In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps ( ...

s before Co are iron isotopes and the main products after are nickel isotopes. Radioactive isotopes can be produced by various nuclear reactions. For example, Co is produced by cyclotron irradiation of iron. The main reaction is the (d,n) reaction Fe + H → n + Co.

List of isotopes

, - , ⁴⁷Co , style="text-align:right" , 27 , style="text-align:right" , 20 , 47.01149(54)# , , , , 7/2−# , , , - , ⁴⁸Co , style="text-align:right" , 27 , style="text-align:right" , 21 , 48.00176(43)# , , p , ⁴⁷Fe , 6+# , , , - , rowspan=2, ⁴⁹Co , rowspan=2 style="text-align:right" , 27 , rowspan=2 style="text-align:right" , 22 , rowspan=2, 48.98972(28)# , rowspan=2, <35 ns , p (>99.9%) , ⁴⁸Fe , rowspan=2, 7/2−# , rowspan=2, , rowspan=2, , - , β⁺ (<.1%) , ⁴⁹Fe , - , rowspan=2, ⁵⁰Co , rowspan=2 style="text-align:right" , 27 , rowspan=2 style="text-align:right" , 23 , rowspan=2, 49.98154(18)# , rowspan=2, 44(4) ms , β⁺, p (54%) , ⁴⁹Mn , rowspan=2, (6+) , rowspan=2, , rowspan=2, , - , β⁺ (46%) , ⁵⁰Fe , - , ⁵¹Co , style="text-align:right" , 27 , style="text-align:right" , 24 , 50.97072(16)# , 60# ms 200 ns, β⁺ , ⁵¹Fe , 7/2−# , , , - , ⁵²Co , style="text-align:right" , 27 , style="text-align:right" , 25 , 51.96359(7)# , 115(23) ms , β⁺ , ⁵²Fe , (6+) , , , - , rowspan=2 style="text-indent:1em" , ^52mCo , rowspan=2 colspan="3" style="text-indent:2em" , 380(100)# keV , rowspan=2, 104(11)# ms , β⁺ , ⁵²Fe , rowspan=2, 2+# , rowspan=2, , rowspan=2, , - , IT , ⁵²Co , - , ⁵³Co , style="text-align:right" , 27 , style="text-align:right" , 26 , 52.954219(19) , 242(8) ms , β⁺ , ⁵³Fe , 7/2−# , , , - , rowspan=2 style="text-indent:1em" , ^53mCo , rowspan=2 colspan="3" style="text-indent:2em" , 3197(29) keV , rowspan=2, 247(12) ms , β⁺ (98.5%) , ⁵³Fe , rowspan=2, (19/2−) , rowspan=2, , rowspan=2, , - , p (1.5%) , ⁵²Fe , - , ⁵⁴Co , style="text-align:right" , 27 , style="text-align:right" , 27 , 53.9484596(8) , 193.28(7) ms , β⁺ , ⁵⁴Fe , 0+ , , , - , style="text-indent:1em" , ^54mCo , colspan="3" style="text-indent:2em" , 197.4(5) keV , 1.48(2) min , β⁺ , ⁵⁴Fe , (7)+ , , , - , ⁵⁵Co , style="text-align:right" , 27 , style="text-align:right" , 28 , 54.9419990(8) , 17.53(3) h , β⁺ , ⁵⁵Fe , 7/2− , , , - , ⁵⁶Co , style="text-align:right" , 27 , style="text-align:right" , 29 , 55.9398393(23) , 77.233(27) d , β⁺ , ⁵⁶Fe , 4+ , , , - , ⁵⁷Co , style="text-align:right" , 27 , style="text-align:right" , 30 , 56.9362914(8) , 271.74(6) d , EC , ⁵⁷Fe , 7/2− , , , - , ⁵⁸Co , style="text-align:right" , 27 , style="text-align:right" , 31 , 57.9357528(13) , 70.86(6) d , β⁺ , ⁵⁸Fe , 2+ , , , - , style="text-indent:1em" , ^58m1Co , colspan="3" style="text-indent:2em" , 24.95(6) keV , 9.04(11) h , IT , ⁵⁸Co , 5+ , , , - , style="text-indent:1em" , ^58m2Co , colspan="3" style="text-indent:2em" , 53.15(7) keV , 10.4(3) μs , , , 4+ , , , - , ⁵⁹Co , style="text-align:right" , 27 , style="text-align:right" , 32 , 58.9331950(7) , colspan="3" style="text-align:center;", Stable , 7/2− , 1.0000 , , - , ⁶⁰Co , style="text-align:right" , 27 , style="text-align:right" , 33 , 59.9338171(7) , 5.2713(8) y , β⁻, γ , ⁶⁰Ni , 5+ , , , - , rowspan=2 style="text-indent:1em" , ^60mCo , rowspan=2 colspan="3" style="text-indent:2em" , 58.59(1) keV , rowspan=2, 10.467(6) min , IT (99.76%) , ⁶⁰Co , rowspan=2, 2+ , rowspan=2, , rowspan=2, , - , β⁻ (.24%) , ⁶⁰Ni , - , ⁶¹Co , style="text-align:right" , 27 , style="text-align:right" , 34 , 60.9324758(10) , 1.650(5) h , β⁻ , ⁶¹Ni , 7/2− , , , - , ⁶²Co , style="text-align:right" , 27 , style="text-align:right" , 35 , 61.934051(21) , 1.50(4) min , β⁻ , ⁶²Ni , 2+ , , , - , rowspan=2 style="text-indent:1em" , ^62mCo , rowspan=2 colspan="3" style="text-indent:2em" , 22(5) keV , rowspan=2, 13.91(5) min , β⁻ (99%) , ⁶²Ni , rowspan=2, 5+ , rowspan=2, , rowspan=2, , - , IT (1%) , ⁶²Co , - , ⁶³Co , style="text-align:right" , 27 , style="text-align:right" , 36 , 62.933612(21) , 26.9(4) s , β⁻ , ⁶³Ni , 7/2− , , , - , ⁶⁴Co , style="text-align:right" , 27 , style="text-align:right" , 37 , 63.935810(21) , 0.30(3) s , β⁻ , ⁶⁴Ni , 1+ , , , - , ⁶⁵Co , style="text-align:right" , 27 , style="text-align:right" , 38 , 64.936478(14) , 1.20(6) s , β⁻ , ⁶⁵Ni , (7/2)− , , , - , ⁶⁶Co , style="text-align:right" , 27 , style="text-align:right" , 39 , 65.93976(27) , 0.18(1) s , β⁻ , ⁶⁶Ni , (3+) , , , - , style="text-indent:1em" , ^66m1Co , colspan="3" style="text-indent:2em" , 175(3) keV , 1.21(1) μs , , , (5+) , , , - , style="text-indent:1em" , ^66m2Co , colspan="3" style="text-indent:2em" , 642(5) keV , >100 μs , , , (8-) , , , - , ⁶⁷Co , style="text-align:right" , 27 , style="text-align:right" , 40 , 66.94089(34) , 0.425(20) s , β⁻ , ⁶⁷Ni , (7/2−)# , , , - , ⁶⁸Co , style="text-align:right" , 27 , style="text-align:right" , 41 , 67.94487(34) , 0.199(21) s , β⁻ , ⁶⁸Ni , (7-) , , , - , style="text-indent:1em" , ^68mCo , colspan="3" style="text-indent:2em" , 150(150)# keV , 1.6(3) s , , , (3+) , , , - , rowspan=2, ⁶⁹Co , rowspan=2 style="text-align:right" , 27 , rowspan=2 style="text-align:right" , 42 , rowspan=2, 68.94632(36) , rowspan=2, 227(13) ms , β⁻ (>99.9%) , ⁶⁹Ni , rowspan=2, 7/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁶⁸Ni , - , rowspan=2, ⁷⁰Co , rowspan=2 style="text-align:right" , 27 , rowspan=2 style="text-align:right" , 43 , rowspan=2, 69.9510(9) , rowspan=2, 119(6) ms , β⁻ (>99.9%) , ⁷⁰Ni , rowspan=2, (6-) , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁶⁹Ni , - , style="text-indent:1em" , ^70mCo , colspan="3" style="text-indent:2em" , 200(200)# keV , 500(180) ms , , , (3+) , , , - , rowspan=2, ⁷¹Co , rowspan=2 style="text-align:right" , 27 , rowspan=2 style="text-align:right" , 44 , rowspan=2, 70.9529(9) , rowspan=2, 97(2) ms , β⁻ (>99.9%) , ⁷¹Ni , rowspan=2, 7/2−# , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁷⁰Ni , - , rowspan=2, ⁷²Co , rowspan=2 style="text-align:right" , 27 , rowspan=2 style="text-align:right" , 45 , rowspan=2, 71.95781(64)# , rowspan=2, 62(3) ms , β⁻ (>99.9%) , ⁷²Ni , rowspan=2, (6- ,7-) , rowspan=2, , rowspan=2, , - , β⁻, n (<.1%) , ⁷¹Ni , - , ⁷³Co , style="text-align:right" , 27 , style="text-align:right" , 46 , 72.96024(75)# , 41(4) ms , , , 7/2−# , , , - , ⁷⁴Co , style="text-align:right" , 27 , style="text-align:right" , 47 , 73.96538(86)# , 50# ms 300 ns, , , 0+ , , , - , ⁷⁵Co , style="text-align:right" , 27 , style="text-align:right" , 48 , 74.96833(86)# , 40# ms 300 ns, , , 7/2−# , ,

Use of cobalt radioisotopes in medicine

Cobalt-57 (Co or Co-57) is used in medical tests; it is used as a radiolabel for vitamin B uptake. It is useful for the Schilling test. Cobalt-60 (Co or Co-60) is used in

radiotherapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...

. It produces two gamma rays with energies of 1.17 MeV and 1.33 MeV. The Co source is about 2 cm in diameter and as a result produces a

geometric Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ca ...

penumbra The umbra, penumbra and antumbra are three distinct parts of a shadow, created by any light source after impinging on an opaque object. Assuming no diffraction, for a collimated beam (such as a point source) of light, only the umbra is cast. Th ...

, making the edge of the

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

field fuzzy. The metal has the unfortunate habit of producing a fine dust, causing problems with radiation protection. The Co source is useful for about 5 years but even after this point is still very radioactive, and so cobalt machines have fallen from favor in the Western world where

linacs A linear particle accelerator (often shortened to linac) is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear bea ...

are common.

Industrial uses for radioactive isotopes

Cobalt-60 (Co) is useful as a gamma ray source because it can be produced in predictable quantities, and for its high radioactivity simply by exposing natural cobalt to neutrons in a reactor. The uses for industrial cobalt include: *Sterilization of medical supplies and

medical waste Biomedical waste or hospital waste is any kind of waste containing infectious (or potentially infectious) materials. It may also include waste associated with the generation of biomedical waste that visually appears to be of medical or laboratory ...

*Radiation treatment of foods for sterilization (cold

pasteurization Pasteurization or pasteurisation is a process of food preservation in which packaged and non-packaged foods (such as milk and fruit juices) are treated with mild heat, usually to less than , to eliminate pathogens and extend shelf life. The ...

) *Industrial radiography (e.g., weld integrity radiographs) *Density measurements (e.g., concrete density measurements) *Tank fill height switches Cobalt-57 is used as a source in Mössbauer spectroscopy of iron-containing samples. Electron capture by Co forms an excited state of the Fe nucleus, which in turn decays to the ground state with emission of a gamma ray. Measurement of the gamma ray spectrum provides information about the chemical state of the iron atom in the sample.

References

* Isotope masses from: ** * Isotopic compositions and standard atomic masses from: ** ** * Half-life, spin, and isomer data selected from the following sources. ** ** ** {{Navbox element isotopes Cobalt Cobalt