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Appearance. 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 ...
Iodine-124 is a proton-rich isotope of iodine with a half-life of 4.18 days. Its modes of decay are: 74.4% electron capture, 25.6% positron emission. 124 I decays to 124 Te. Iodine-124 can be made by numerous nuclear reactions via a cyclotron. The most common starting material used is 124 Te.
When a chemical symbol is used, e.g. "C" for carbon, standard notation (now known as "AZE notation" because A is the mass number, Z the atomic number, and E for element) is to indicate the mass number (number of nucleons) with a superscript at the upper left of the chemical symbol and to indicate the atomic number with a subscript at the lower ...
Potassium (. 19K) has 25 known isotopes from 34. K to 57. K as well as 31. K, as well as an unconfirmed report of 59. K. [3] Three of those isotopes occur naturally: the two stable forms 39. K (93.3%) and 41. K (6.7%), and a very long-lived radioisotope 40.
Chemical symbol. The periodic table, elements being denoted by their symbols. Chemical symbols are the abbreviations used in chemistry, mainly for chemical elements; but also for functional groups, chemical compounds, and other entities. Element symbols for chemical elements, also known as atomic symbols, normally consist of one or two letters ...
Hydrogen (1 H) has three naturally occurring isotopes: 1 H, 2 H, and 3 H. 1 H and 2 H are stable, while 3 H has a half-life of 12.32 (2) years. [ 3 ][ nb 1 ] Heavier isotopes also exist; all are synthetic and have a half-life of less than 1 zeptosecond (10 −21 s). [ 4 ][ 5 ] Of these, 5 H is the least stable, while 7 H is the most.
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 two isomers (22m. Na and 24m. 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 28(2).
List of chemical elements. 118 chemical elements have been identified and named officially by IUPAC. A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [1]