We are looking at defining the terms chemical formula, chemical symbol, and chemical equation. A chemical symbol is really another name for an atomic symbol found on the periodic table. It is the one or two letter designation for each atom found on the periodic table. An example would be Na for sodium.
A chemical formula is the combination of atomic symbols that designate a particular chemical compound, or a substance with two or more different elements. The formula shows which type and how many of each element makes up that particular compound. An example would be NaCl for sodium chloride, composed of one atom of sodium and one atom of chlorine.
A chemical equation shows one or more chemical compounds (reactants) being converted into different chemical species called products. If the equation is balanced, it shows the ratios that the compounds must be present in to react and how many of the different products are produced. An arrow symbol is used to separate the left hand side from the right hand side of the equation (like an equals sign in a math equation).