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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.
It is prevented from having a stable isotope with 4 protons and 6 neutrons by the very large mismatch in proton/neutron ratio for such a light element. (Nevertheless, beryllium-10 has a half-life of 1.36 million years, which is too short to be primordial, but still indicates unusual stability for a light isotope with such an imbalance.)
The symbols for isotopes of elements other than hydrogen and radon are no longer used in the scientific community. Many of these symbols were designated during the early years of radiochemistry , and several isotopes (namely those in the decay chains of actinium , radium , and thorium ) bear placeholder names using the early naming system ...
Hydrogen is the only element whose isotopes have different names that remain in common use today: 2 H is deuterium [6] and 3 H is tritium. [7] The symbols D and T are sometimes used for deuterium and tritium; IUPAC ( International Union of Pure and Applied Chemistry ) accepts said symbols, but recommends the standard isotopic symbols 2 H and 3 ...
Isotopes of an element are distinguished by mass number (total protons and neutrons), with this number combined with the element's symbol. IUPAC prefers that isotope symbols be written in superscript notation when practical, for example 12 C and 235 U. However, other notations, such as carbon-12 and uranium-235, or C-12 and U-235, are also used.
Radioactive isotopes ranging from 11 O to 28 O have also been characterized, all short-lived. The longest-lived radioisotope is 15 O with a half-life of 122.266(43) s, while the shortest-lived isotope is the unbound 11 O with a half-life of 198(12) yoctoseconds, though half-lives have not been measured for the unbound heavy isotopes 27 O and 28 ...
Oxygen-16 (symbol: 16 O or 16 8 O) is a nuclide. It is a stable isotope of oxygen, with 8 neutrons and 8 protons in its nucleus, and when not ionized, 8 electrons orbiting the nucleus. Oxygen-16 has a mass of 15.994 914 619 56 u. It is the most abundant isotope of oxygen and accounts for 99.757% of oxygen's natural abundance. [2]
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess numbers of either neutrons or protons, ...