Search results
Results from the WOW.Com Content Network
The number of protons (Z column) and number of neutrons (N column). energy column The column labeled "energy" denotes the energy equivalent of the mass of a neutron minus the mass per nucleon of this nuclide (so all nuclides get a positive value) in MeV, formally: m n − m nuclide / A, where A = Z + N is the mass number. Note that this means ...
The only stable nuclides having an odd number of protons and an odd number of neutrons are hydrogen-2, lithium-6, boron-10, nitrogen-14 and (observationally) tantalum-180m. This is because the mass–energy of such atoms is usually higher than that of their neighbors on the same isobaric chain, so most of them are unstable to beta decay .
Interactive Chart of Nuclides (Brookhaven National Laboratory) The Lund/LBNL Nuclear Data Search; An isotope table with clickable information on every isotope and its decay routes is available at chemlab.pc.maricopa.edu; An example of free Universal Nuclide Chart with decay information for over 3000 nuclides is available at Nucleonica.net.
A set of nuclides with equal proton number (atomic number), i.e., of the same chemical element but different neutron numbers, are called isotopes of the element. Particular nuclides are still often loosely called "isotopes", but the term "nuclide" is the correct one in general (i.e., when Z is not fixed).
These nuclides lie at the very bottom of the valley of stability. From this bottom, the average binding energy per nucleon slowly decreases with increasing atomic mass number. The heavy nuclide 238 U is not stable, but is slow to decay with a half-life of 4.5 billion years. [1] It has relatively small binding energy per nucleon.
Interactive Chart of Nuclides (Brookhaven National Laboratory) The Lund/LBNL Nuclear Data Search; An isotope table with clickable information on every isotope and its decay routes is available at chemlab.pc.maricopa.edu; An example of free Universal Nuclide Chart with decay information for over 3000 nuclides is available at Nucleonica.net.
These 35 radioactive naturally occurring nuclides comprise the radioactive primordial nuclides. The total number of primordial nuclides is then 251 (the stable nuclides) plus the 35 radioactive primordial nuclides, for a total of 286 primordial nuclides. This number is subject to change if new shorter-lived primordials are identified on Earth.
For many elements with atomic number Z small enough to occupy only the first three nuclear shells, that is up to that of calcium (Z = 20), there exists a stable isotope with N/Z ratio of one. The exceptions are beryllium ( N / Z = 1.25) and every element with odd atomic number between 9 and 19 inclusive (though in those cases N = Z + 1 always ...