In nuclear physics and nuclear chemistry, isobars<\/strong> are nuclides of different elements with the same mass number (same number of nucleons). An example of a series of isobars would be Te-135, I-135, and Xe-135, responsible for xenon poisoning in nuclear reactors.<\/div><\/div>\n
In nuclear physics and nuclear chemistry, the various species of atoms whose nuclei contain particular numbers of protons and neutrons are called nuclides<\/strong>. Nuclides are also characterized by their nuclear energy states (e.g., metastable nuclide ^{242m<\/sup>Am). Each nuclide is denoted by the chemical symbol of the element (this specifies Z) with the atomic mass number as a superscript. Hydrogen (H), for example, consists of one electron and one proton. The number of neutrons <\/strong><\/a>in a nucleus is known as the neutron number <\/strong>and is given the symbol N<\/strong>. The total number of nucleons, protons, and neutrons in a nucleus are equal to Z + N = A<\/strong>, where A is called the atomic mass number<\/strong>.<\/p>\n}
$\"Proton$ <\/a>Isobars<\/strong> are nuclides of different elements with the same mass number (same number of nucleons). An example of a series of isobars would be Te-135, I-135, and Xe-135, responsible for xenon poisoning in nuclear reactors. The nuclei of these nuclides all contain 135 nucleons; however, they contain varying numbers of protons and neutrons.<\/p>\n
The term \u201cisobars\u201d (originally \u201cisobares\u201d) for nuclides was suggested by British chemist Alfred Walter Stewart in 1918. It is derived from the Greek word isos, meaning \u201cequal,\u201d and baros, meaning \u201cweight.\u201d<\/p>\n
As can be seen, isobars have the same mass number. The atomic\u00a0mass number<\/strong> determines especially the atomic mass of atoms. The mass number is different for each different isotope of a chemical element. The mass number<\/strong> is written either after the element name or as a superscript to the left of an element\u2019s symbol. For example, the most common isotope of carbon is carbon-12 or ^{12<\/sup>C.<\/p>\n}
For ^{12<\/sup>C, the atomic mass is exactly 12u since the atomic mass unit is defined from it. The isotopic mass usually differs for other isotopes and is usually within 0.1 u of the mass number. For example, ^{63<\/sup><\/strong>Cu<\/strong> (29 protons and 34 neutrons) has a mass number of 63, and an isotopic mass in its nuclear ground state is 62.91367 u.<\/strong><\/p>\n}}
There are two reasons for the difference between mass number and isotopic mass, known as the mass defect<\/a>:<\/p>\n
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The neutron is<\/strong> slightly heavier<\/strong> than the proton<\/strong>, increasing the mass of nuclei with more neutrons than protons relative to the atomic mass unit scale based on ^{12<\/sup>C with equal numbers of protons and neutrons.<\/li>\n}
The nuclear binding energy<\/a> varies between nuclei, and a nucleus with greater binding energy has lower total energy and a lower mass<\/strong> according to Einstein\u2019s mass-energy equivalence<\/a> relation E<\/em> = mc<\/em>^{2<\/sup>. For ^{63<\/sup><\/strong>Cu,<\/strong> the atomic mass is less than 63, so this must be the dominant factor.<\/li>\n<\/ol>\n}} $\"Nuclide$ <\/a>
Segre chart – This chart shows a plot of the known nuclides as a function of their atomic and neutron numbers. It can be observed from the chart that there are more neutrons than protons in nuclides with Z greater than about 20 (Calcium). These extra neutrons are necessary for the stability of the heavier nuclei, and the excess neutrons act somewhat like nuclear glue.<\/figcaption><\/figure>\n
l<\/p>\n
<\/span>References:<\/div>
Nuclear and Reactor Physics:<\/strong>\n\n
J. R. Lamarsh, Introduction to Nuclear Reactor Theory, 2nd ed., Addison-Wesley, Reading,\u00a0MA (1983).<\/li>\n
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.<\/li>\n
W. M. Stacey, Nuclear Reactor Physics, John Wiley & Sons, 2001, ISBN: 0- 471-39127-1.<\/li>\n
Glasstone, Sesonske. Nuclear Reactor Engineering: Reactor Systems Engineering,\u00a0Springer; 4th edition, 1994, ISBN:\u00a0978-0412985317<\/li>\n
W.S.C. Williams. Nuclear and Particle Physics.\u00a0Clarendon Press; 1 edition, 1991, ISBN:\u00a0978-0198520467<\/li>\n
G.R.Keepin. Physics of Nuclear Kinetics.\u00a0Addison-Wesley Pub. Co; 1st edition, 1965<\/li>\n
Robert Reed Burn, Introduction to Nuclear Reactor Operation, 1988.<\/li>\n
U.S. Department of Energy, Nuclear Physics and Reactor Theory.\u00a0DOE Fundamentals Handbook,\u00a0Volume 1 and 2.\u00a0January\u00a01993.<\/li>\n
Paul Reuss, Neutron Physics.\u00a0EDP Sciences, 2008.\u00a0ISBN: 978-2759800414.<\/li>\n<\/ol>\n
<\/strong>Advanced Reactor Physics:<\/strong><\/p>\n
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K. O. Ott, W. A. Bezella, Introductory Nuclear Reactor Statics, American Nuclear Society, Revised edition (1989), 1989, ISBN: 0-894-48033-2.<\/li>\n
K. O. Ott, R. J. Neuhold, Introductory Nuclear Reactor Dynamics, American Nuclear Society, 1985, ISBN: 0-894-48029-4.<\/li>\n
D. L. Hetrick, Dynamics of Nuclear Reactors, American Nuclear Society, 1993, ISBN: 0-894-48453-2.\u00a0<\/span><\/li>\n
E. E. Lewis, W. F. Miller, Computational Methods of Neutron Transport, American Nuclear Society, 1993, ISBN: 0-894-48452-4.<\/li>\n<\/ol>\n<\/div><\/div>
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See above:<\/h2>\n
Nuclide<\/i> <\/span><\/a><\/p><\/div><\/div>
<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"In nuclear physics and nuclear chemistry, the various species of atoms whose nuclei contain particular numbers of protons and neutrons are called nuclides. Nuclides are also characterized by their nuclear energy states (e.g., metastable nuclide 242mAm). Each nuclide is denoted by the chemical symbol of the element (this specifies Z) with the atomic mass number … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":24014,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"generate_page_header":""},"_links":{"self":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/24020"}],"collection":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/comments?post=24020"}],"version-history":[{"count":3,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/24020\/revisions"}],"predecessor-version":[{"id":37719,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/24020\/revisions\/37719"}],"up":[{"embeddable":true,"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/pages\/24014"}],"wp:attachment":[{"href":"https:\/\/sitepourvtc.com\/wp-json\/wp\/v2\/media?parent=24020"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}