Search results
Results from the WOW.Com Content Network
Of the 26 "monoisotopic" elements that have only a single stable isotope, all but one have an odd atomic number—the single exception being beryllium. In addition, no odd-numbered element has more than two stable isotopes, while every even-numbered element with stable isotopes, except for helium, beryllium, and carbon, has at least three.
This is a list of radioactive nuclides (sometimes also called isotopes), ordered by half-life from shortest to longest, in seconds, minutes, hours, days and years. Current methods make it difficult to measure half-lives between approximately 10 −19 and 10 −10 seconds.
The first isotope to be discovered (in fallout from nuclear testing) was 255 Fm in 1952. 250 Fm was independently synthesized shortly after the discovery of 255 Fm. There are 20 known radioisotopes ranging in atomic mass from 241 Fm to 260 Fm ( 260 Fm is unconfirmed), and 4 nuclear isomers , 247m Fm, 250m Fm, 251m Fm, and 253m Fm.
A nuclide is a species of an atom with a specific number of protons and neutrons in the nucleus, for example, carbon-13 with 6 protons and 7 neutrons. The nuclide concept (referring to individual nuclear species) emphasizes nuclear properties over chemical properties, whereas the isotope concept (grouping all atoms of each element) emphasizes chemical over nuclear.
A table or chart of nuclides is a two-dimensional graph of isotopes of the elements, in which one axis represents the number of neutrons (symbol N) and the other represents the number of protons (atomic number, symbol Z) in the atomic nucleus. Each point plotted on the graph thus represents a nuclide of a known or hypothetical chemical element.
It is also the isotope with the lowest mass per nucleon, 930.412 MeV/c 2, though not the isotope with the highest nuclear binding energy per nucleon, which is nickel-62. [7] However, because of the details of how nucleosynthesis works, 56 Fe is a more common endpoint of fusion chains inside supernovae , where it is mostly produced as 56 Ni.
There are 20 isotopes of sodium (11 Na), ranging from 17 Na to 39 Na (except for the still-unknown 36 Na and 38 Na), [4] and five isomers (two for 22 Na, and one each for 24 Na, 26 Na, and 32 Na). 23 Na is the only stable (and the only primordial) isotope. It is considered a monoisotopic element and it has a standard atomic weight of 22.989 769 ...
Galindo-Uribarri and co-workers chose an isotope of neon with an energy structure that prevents it from emitting protons one at a time. This means the two protons are ejected simultaneously. The team fired a beam of fluorine ions at a proton-rich target to produce 18 Ne, which then decayed into oxygen and two protons. Any protons ejected from ...