Nickel-62 is an isotope Isotopes are different types of atoms of the same chemical element, each having a different number of neutrons. In a corresponding manner, isotopes differ in mass number (or number of nucleons) but never in atomic number. The number of protons (the atomic number) is the same because that is what characterizes a chemical element. For example, of nickel Nickel is a chemical element, with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. It is one of the four ferromagnetic elements that exist around room temperature, the other three being iron, cobalt and gadolinium having 28 protons The proton is a subatomic particle with an electric charge of +1 elementary charge. It is found in the nucleus of each atom, along with neutrons, but is also stable by itself and has a second identity as the hydrogen ion, H+. It is composed of three fundamental particles: two up quarks and one down quark and 34 neutrons The neutron is a subatomic particle with no net electric charge and a mass slightly larger than that of a proton. They are usually found in atomic nuclei. The nuclei of most atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of protons in a nucleus is the atomic number and defines the type.

It is a stable isotope Stable isotopes are chemical isotopes that are not radioactive . By this definition, there are 256 known stable isotopes of those 80 elements which have one or more stable nuclides. A list of these is given at the end of this article. Of these 80, twenty-six have only a single stable isotope, and are thus termed monoisotopic, and the rest have, and in fact has the highest nuclear binding energy Binding energy is the mechanical energy required to disassemble a whole into separate parts. A bound system has typically a lower potential energy than its constituent parts; this is what keeps the system together. The usual convention is that this corresponds to a positive binding energy of any known nuclide A nuclide is an atomic species characterized by the specific constitution of its nucleus, i.e., by its number of protons Z, its number of neutrons N, and its energy state. Thus, all nuclides are atoms which have at least one electron (though certain ions may be included), but naked nuclei (such as occur in cosmic rays and sufficiently hot plasmas) (8.7945 MeV/nucleon).[1] A widespread misconception attributes this fact to the isotope of iron-56 Nickel-62 has a higher binding energy per nucleon; this is consistent with having a higher mass per nucleon because nickel-62 has a greater proportion of neutrons; which are slightly more massive than protons, which has the lowest mass per nucleon A nucleon is a collective name for two baryons: the neutron and the proton in physics. They are constituents of the atomic nucleus and until the 1960s were thought to be elementary particles. In those days their interactions defined strong interactions. Now they are known to be composite particles, made of quarks. Understanding the properties of of all nuclides. This misconceptions probably originated from astrophysics.[2] During nucleosynthesis Stellar nucleosynthesis is the collective term for the nuclear reactions taking place in stars to build the nuclei of the elements heavier than hydrogen. Some small quantity of these reactions also occur on the stellar surface under various circumstances in stars the competition between photodisintegration Photodisintegration is a physical process in which an extremely high energy gamma ray interacts with an atomic nucleus and causes it to enter an excited state, which immediately decays by emitting a subatomic particle. A single proton or neutron is effectively knocked out of the nucleus by the incoming gamma ray. This process is essentially the and alpha capturing The Alpha process is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements, the other being the triple-alpha process. While the triple-alpha process only requires helium, once some carbon is present, other reactions that consume helium are possible: causes more 56Ni to be produced than 62Ni (56Fe is produced later in the star's ejection shell as 56Ni decays). The 56Ni is the natural end product of silicon-burning at the end of a supernova's life and is the product of 14 alpha captures in the alpha process The Alpha process is one of two classes of nuclear fusion reactions by which stars convert helium into heavier elements, the other being the triple-alpha process. While the triple-alpha process only requires helium, once some carbon is present, other reactions that consume helium are possible: which builds more massive elements in steps of 4 nucleons, from carbon. This alpha process in supernovae burning because of the higher energy of zinc-60, which would be the next step, after addition of another "alpha" (or more properly termed, helium nucleus).

The high binding energy of nickel isotopes in general makes nickel an "end product" of many nuclear reactions (including neutron capture reactions) throughout the universe The Universe is commonly defined as the totality of everything that exists, including all physical matter and energy, the planets, stars, galaxies, and the contents of intergalactic space, although this usage may differ with the context . The term Universe may be used in slightly different contextual senses, denoting such concepts as the cosmos, and accounts for the high relative abundance of nickel—although most of the nickel in space (and thus produced by supernova explosions) is nickel-58 (the most common isotope) and nickel-60 (the second-most, with the other stable isotopes (nickel-61, nickel-62, and nickel-64) being quite rare. This suggests that most nickel is produced in supernovas in the r-process The r-process is a nucleosynthesis process, likely occurring in core-collapse supernovae responsible for the creation of approximately half of the neutron-rich atomic nuclei that are heavier than iron. The process entails a succession of rapid neutron captures on iron seed nuclei, hence the name r-process. The other predominant mechanism for the of neutron capture by nickel-56 immediately after the core-collapse, with any nickel-56 that escapes the supernova explosion rapidly decaying to cobalt-56 and then stable iron-56.

The second and third most tightly bound nuclei are those of 58Fe and 56Fe, with binding energies of 8.7922 MeV/nucleon and 8.7903 MeV/nucleon, respectively.[3]

In spite of having a lower nuclear binding energy than 62Ni, the isotope 56Fe has the lowest mass per nucleon of any nuclide, 930.412 MeV/c2, followed by 62Ni with 930.417 MeV/c2 and 60Ni with 930.420 MeV/c2. This is not a contradiction because 62Ni has a greater proportion of neutrons which are more massive than protons.

If one looks only at the nuclei proper, without including the electron cloud, 56Fe has again the lowest mass per nucleon (930.175 MeV/c2), followed by 60Ni (930.181 MeV/c2) and 62Ni (930.187 MeV/c2).

See also

References

  1. ^ The Most Tightly Bound Nuclei
  2. ^ Fewell, M. P. (1995) "The atomic nuclide with the highest mean binding energy," American Journal of Physics 63 (7): 653-58.
  3. ^ WWW Table of Atomic Masses. G. Audi, A.H. Wapstra and C. Thibault (2003). Nuclear Physics A, 729, p. 337.

Categories: Isotopes of nickel

Personal tools
Namespaces
">
Variants
Views
">
Actions
Search">
The Central London Railway was a railway company established in 1889 to construct a deep-level underground "tube" railway in London. Funding for construction was obtained in 1895 through a syndicate of financiers and construction work took place from 1896 to 1900. When opened in 1900, the railway served 13 stations and ran completely
Navigation
Interaction
Toolbox
Print/export
Languages

 

The above information uses material from Wikipedia and is licensed under the GNU Free Documentation License The purpose of this License is to make a manual, textbook, or other functional and useful document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a.
Some facts may not have been fully verified for accuracy. [Disclaimers Wikipedia is an online open-content collaborative encyclopedia, that is, a voluntary association of individuals and groups working to develop a common resource of human knowledge. The structure of the project allows anyone with an Internet connection to alter its content. Please be advised that nothing found here has necessarily been reviewed by]
This page was last archived by our server on Sat Jul 24 01:04:09 2010. [ refresh local cache ]
Displaying this page or its contents does not use any Wikimedia Foundation's resources.
The owners of this site proudly support the Wikimedia Foundation.

[Hide]▼
[Hide]▲