Английская Википедия:Isotopes of cobalt
Шаблон:Short description Шаблон:Infobox cobalt isotopes Naturally occurring cobalt (Шаблон:SubCo) consists of a single stable isotope, Шаблон:SupCo (thus, cobalt is a mononuclidic element). Twenty-eight radioisotopes have been characterized; the most stable are [[Cobalt-60|Шаблон:SupCo]] with a half-life of 5.2714 years, Шаблон:SupCo (271.8 days), Шаблон:SupCo (77.27 days), and Шаблон:SupCo (70.86 days). All other isotopes have half-lives of less than 18 hours and most of these have half-lives of less than 1 second. This element also has 11 meta states, all of which have half-lives of less than 15 minutes.
The isotopes of cobalt range in atomic weight from Шаблон:SupCo to Шаблон:SupCo. The main decay mode for isotopes with atomic mass less than that of the stable isotope, Шаблон:SupCo, is electron capture and the main mode of decay for those of greater than 59 atomic mass units is beta decay. The main decay products before Шаблон:SupCo are iron isotopes and the main products after are nickel isotopes.
Radioactive isotopes can be produced by various nuclear reactions. For example, Шаблон:SupCo is produced by cyclotron irradiation of iron. The main reaction is the (d,n) reaction Шаблон:SupFe + Шаблон:SupH → n + Шаблон:SupCo.[1]
List of isotopes
Шаблон:Isotopes table |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 20 | 47.01149(54)# | | | | 7/2−# | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 21 | 48.00176(43)# | | p | Шаблон:SupFe | 6+# | | |- | rowspan=2|Шаблон:SupCo | 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%) | Шаблон:SupFe | rowspan=2|7/2−# | rowspan=2| | rowspan=2| |- | [[beta decay|βШаблон:Sup]] (<.1%) | Шаблон:SupFe |- | rowspan=2|Шаблон:SupCo | rowspan=2 style="text-align:right" | 27 | rowspan=2 style="text-align:right" | 23 | rowspan=2|49.98154(18)# | rowspan=2|44(4) ms | βШаблон:Sup, p (54%) | Шаблон:SupMn | rowspan=2|(6+) | rowspan=2| | rowspan=2| |- | βШаблон:Sup (46%) | Шаблон:SupFe |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 24 | 50.97072(16)# | 60# ms [>200 ns] | βШаблон:Sup | Шаблон:SupFe | 7/2−# | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 25 | 51.96359(7)# | 115(23) ms | βШаблон:Sup | Шаблон:SupFe | (6+) | | |- | rowspan=2 style="text-indent:1em" | Шаблон:SupCo | rowspan=2 colspan="3" style="text-indent:2em" | 380(100)# keV | rowspan=2|104(11)# ms | βШаблон:Sup | Шаблон:SupFe | rowspan=2|2+# | rowspan=2| | rowspan=2| |- | IT | Шаблон:SupCo |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 26 | 52.954219(19) | 242(8) ms | βШаблон:Sup | Шаблон:SupFe | 7/2−# | | |- | rowspan=2 style="text-indent:1em" | Шаблон:SupCo | rowspan=2 colspan="3" style="text-indent:2em" | 3197(29) keV | rowspan=2|247(12) ms | βШаблон:Sup (98.5%) | Шаблон:SupFe | rowspan=2|(19/2−) | rowspan=2| | rowspan=2| |- | p (1.5%) | Шаблон:SupFe |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 27 | 53.9484596(8) | 193.28(7) ms | βШаблон:Sup | Шаблон:SupFe | 0+ | | |- | style="text-indent:1em" | Шаблон:SupCo | colspan="3" style="text-indent:2em" | 197.4(5) keV | 1.48(2) min | βШаблон:Sup | Шаблон:SupFe | (7)+ | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 28 | 54.9419990(8) | 17.53(3) h | βШаблон:Sup | Шаблон:SupFe | 7/2− | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 29 | 55.9398393(23) | 77.233(27) d | βШаблон:Sup | Шаблон:SupFe | 4+ | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 30 | 56.9362914(8) | 271.74(6) d | EC | Шаблон:SupFe | 7/2− | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 31 | 57.9357528(13) | 70.86(6) d | βШаблон:Sup | Шаблон:SupFe | 2+ | | |- | style="text-indent:1em" | Шаблон:SupCo | colspan="3" style="text-indent:2em" | 24.95(6) keV | 9.04(11) h | IT | Шаблон:SupCo | 5+ | | |- | style="text-indent:1em" | Шаблон:SupCo | colspan="3" style="text-indent:2em" | 53.15(7) keV | 10.4(3) μs | | | 4+ | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 32 | 58.9331950(7) | colspan="3" style="text-align:center;"|Stable | 7/2− | 1.0000 | |- | [[Cobalt-60|Шаблон:SupCo]] | style="text-align:right" | 27 | style="text-align:right" | 33 | 59.9338171(7) | 5.2714(6) y | βШаблон:Sup, γ | Шаблон:SupNi | 5+ | | |- | rowspan=2 style="text-indent:1em" | Шаблон:SupCo | rowspan=2 colspan="3" style="text-indent:2em" | 58.59(1) keV | rowspan=2|10.467(6) min | IT (99.76%) | Шаблон:SupCo | rowspan=2|2+ | rowspan=2| | rowspan=2| |- | βШаблон:Sup (.24%) | Шаблон:SupNi |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 34 | 60.9324758(10) | 1.650(5) h | βШаблон:Sup | Шаблон:SupNi | 7/2− | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 35 | 61.934051(21) | 1.50(4) min | βШаблон:Sup | Шаблон:SupNi | 2+ | | |- | rowspan=2 style="text-indent:1em" | Шаблон:SupCo | rowspan=2 colspan="3" style="text-indent:2em" | 22(5) keV | rowspan=2|13.91(5) min | βШаблон:Sup (99%) | Шаблон:SupNi | rowspan=2|5+ | rowspan=2| | rowspan=2| |- | IT (1%) | Шаблон:SupCo |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 36 | 62.933612(21) | 26.9(4) s | βШаблон:Sup | Шаблон:SupNi | 7/2− | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 37 | 63.935810(21) | 0.30(3) s | βШаблон:Sup | Шаблон:SupNi | 1+ | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 38 | 64.936478(14) | 1.20(6) s | βШаблон:Sup | Шаблон:SupNi | (7/2)− | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 39 | 65.93976(27) | 0.18(1) s | βШаблон:Sup | Шаблон:SupNi | (3+) | | |- | style="text-indent:1em" | Шаблон:SupCo | colspan="3" style="text-indent:2em" | 175(3) keV | 1.21(1) μs | | | (5+) | | |- | style="text-indent:1em" | Шаблон:SupCo | colspan="3" style="text-indent:2em" | 642(5) keV | >100 μs | | | (8-) | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 40 | 66.94089(34) | 0.425(20) s | βШаблон:Sup | Шаблон:SupNi | (7/2−)# | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 41 | 67.94487(34) | 0.199(21) s | βШаблон:Sup | Шаблон:SupNi | (7-) | | |- | style="text-indent:1em" | Шаблон:SupCo | colspan="3" style="text-indent:2em" | 150(150)# keV | 1.6(3) s | | | (3+) | | |- | rowspan=2|Шаблон:SupCo | rowspan=2 style="text-align:right" | 27 | rowspan=2 style="text-align:right" | 42 | rowspan=2|68.94632(36) | rowspan=2|227(13) ms | βШаблон:Sup (>99.9%) | Шаблон:SupNi | rowspan=2|7/2−# | rowspan=2| | rowspan=2| |- | βШаблон:Sup, n (<.1%) | Шаблон:SupNi |- | rowspan=2|Шаблон:SupCo | rowspan=2 style="text-align:right" | 27 | rowspan=2 style="text-align:right" | 43 | rowspan=2|69.9510(9) | rowspan=2|119(6) ms | βШаблон:Sup (>99.9%) | Шаблон:SupNi | rowspan=2|(6-) | rowspan=2| | rowspan=2| |- | βШаблон:Sup, n (<.1%) | Шаблон:SupNi |- | style="text-indent:1em" | Шаблон:SupCo | colspan="3" style="text-indent:2em" | 200(200)# keV | 500(180) ms | | | (3+) | | |- | rowspan=2|Шаблон:SupCo | rowspan=2 style="text-align:right" | 27 | rowspan=2 style="text-align:right" | 44 | rowspan=2|70.9529(9) | rowspan=2|97(2) ms | βШаблон:Sup (>99.9%) | Шаблон:SupNi | rowspan=2|7/2−# | rowspan=2| | rowspan=2| |- | βШаблон:Sup, n (<.1%) | Шаблон:SupNi |- | rowspan=2|Шаблон:SupCo | rowspan=2 style="text-align:right" | 27 | rowspan=2 style="text-align:right" | 45 | rowspan=2|71.95781(64)# | rowspan=2|62(3) ms | βШаблон:Sup (>99.9%) | Шаблон:SupNi | rowspan=2|(6- ,7-) | rowspan=2| | rowspan=2| |- | βШаблон:Sup, n (<.1%) | Шаблон:SupNi |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 46 | 72.96024(75)# | 41(4) ms | | | 7/2−# | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 47 | 73.96538(86)# | 50# ms [>300 ns] | | | 0+ | | |- | Шаблон:SupCo | style="text-align:right" | 27 | style="text-align:right" | 48 | 74.96833(86)# | 40# ms [>300 ns] | | | 7/2−# | | Шаблон:Isotopes table/footer
Use of cobalt radioisotopes in medicine Шаблон:Anchor
Cobalt-57 (Шаблон:SupCo or Co-57) is used in medical tests; it is used as a radiolabel for vitamin BШаблон:Sub uptake. It is useful for the Schilling test.[2]
Cobalt-60 (Шаблон:SupCo or Co-60) is used in radiotherapy. It produces two gamma rays with energies of 1.17 MeV and 1.33 MeV. The Шаблон:SupCo source is about 2 cm in diameter and as a result produces a geometric penumbra, making the edge of the radiation field fuzzy. The metal has the unfortunate habit of producing fine dust, causing problems with radiation protection. The Шаблон:SupCo source is useful for about 5 years but even after this point is still very radioactive, and so cobalt machines have fallen from favour in the Western world where linacs are common.
Industrial uses for radioactive isotopes
Cobalt-60 (Шаблон:SupCo) 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.[3] The uses for industrial cobalt include:
- Sterilization of medical supplies and medical waste
- Radiation treatment of foods for sterilization (cold pasteurization)[4]
- 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 Шаблон:SupCo forms an excited state of the Шаблон:SupFe nucleus, which in turn decays to the ground state with the 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.
Шаблон:Navbox element isotopes
