Nuclide symbols

Nuclide Symbol Mass Number Atomic Number Half-life3 Major Decay Mode"... 

An isotopically substituted compound has a composition such that all of the molecules of the compound have only the indicated nuclides at the designated positions. To indicate isotopic substitution in formulas, the nuclide symbols are incorporated into the formulas. To indicate isotopic substitution in spelled-out compound names, the number and symbol (and locants if needed) are placed in parentheses closed up to the name. 

M,A) compare with atomic number and atomic weight. The total number of protons and neutrons in an atom or ion. In nuclide symbols the mass number is given as a leading superscript. In isotope names (e. g. carbon-14, sodium-23) the mass number is the number following the element name. 

There are two main methods used for naming isotopically labelled compounds. For specifically labelled compounds, lUPAC recommends forming the name by placing the nuclide symbols (plus locants if necessary) in square brackets before the name of the unlabelled compounds or that part of the name which is isotopically modified. 

Chemical Abstracts uses the Boughton system, in which italicized nuclide symbols follow the name or part of the name of the unlabelled compound as shown below. The symbols -d and -t are used to denote deuterium and tritium, respectively. 

In isotopically modified compounds, a principle governs the order of citation of nuclide symbols. (See Section II-2.2.5 of Ref. 2.)... 

IR-4.5.1 General formalism The mass number of any specific nuclide can be indicated in the usual way with a left superscript preceding the appropriate atomic symbol (see Section IR-3.2). When it is necessary to cite different nuclides at the same position in a formula, the nuclide symbols are written in alphabetical order when their atomic symbols are identical the order is that of increasing mass number. Isotopically modified compounds may be classified as isotopically substituted compounds and isotopically labelled compounds. 

IR-4.5.3.2 Specifically labelled compounds An isotopically labelled compound is called a specifically labelled compound when a unique isotopically substituted compound is added formally to the analogous isotopically unmodified compound. A specifically labelled compound is indicated by enclosing the appropriate nuclide symbol(s) and multiplying subscript (if any) in square brackets. 

A selectively labelled compound may be considered as a mixture of specifically labelled compounds. It is indicated by prefixing the formula by the nuclide symbol(s) preceded by any necessary locant(s) (but without multiplying subscripts) enclosed in square brackets. 

The mass number for normal hydrogen atoms is 1 for deuterium, 2 and for tritium, 3. The composition of a nucleus is indicated by its nuclide symbol. This consists of the symbol for the element (E), with the atomic number (Z) written as a subscript at the lower left and the mass number (A) as a superscript at the upper left, By this system, the three isotopes of hydrogen are designated as H, H, and ]H. 

Knowing that the number at the bottom left of the nuclide symbol is the atomic number or number of protons, we can verify the identity of the element in addition to knowing the number or protons per nuclide. From the mass number at the top left, we know the number of protons plus neutrons. The number of protons (atomic number) minus the number of electrons must equal the charge, if any, shown at the top right. From these data one can determine if two nuclides have the same number of protons and are therefore the same element. If they are the same element, they wiU be isotopes only if their mass numbers differ. 

Name Symbol Nuclide Symbol Mass (amu) Atomic Abundance in Nature No. of Protons No. of Neutrons No. of Electrons (in neutral) atoms)... 

The sum of the mass numbers (the left superscript in the nuclide symbol) of the reactants must equal the sum of the mass numbers of the products. 

A nuclide that has 26 protons and 33 neutrons is used to study blood chemistry. Write its nuclide symbol in the form of 2X. Write two other ways to represent this nuclide. 

One of the nuclides used in radiation therapy for the treatment of cancer has 39 protons and 51 neutrons. Write its nuclide symbol in the form of zX. Write two... 

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