Symbols Used in Nuclear Reactions

Chemists usually study four fundamental kinds of nuclear reactions  

A nuclide is a specific nuclear species characterized by its proton number Z and its neutron number N. 

Isotopes are nuclides with the same number of protons but a different number of neutrons. 

In each case, the electrons in the atoms are ignored. All of the symbols used to write equations for nuclear reactions represent only the atomic nuclei. Recall that we said we write the symbol for an isotope in the form, where X is the symbol for the element, Z is the element s atomic number (which is determined by the number of protons in atoms of that element), and A is the element s mass number (the sum of the number of protons and neutrons in atoms of that isotope). If we are concerned only with an atom s nucleus, we may also use the term nuclide instead of isotope, since the term isotope commonly refers to the entire atom and includes the atom s electrons. 

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