text: The only identifier of an element is the number of protons. \n\nAny atom with only 1 proton is hydrogen,  8 protons is Oxygen,  etc.\n\nThe element with 11 protons is Sodium (Na).   The different numbers of Neutrons identify the isotope.  The Notation is a superscript prior to the item showing the total weight.  In this case, 23NA.\n\nThe link below also shows all of the known isotopes (and how they're written).