Chemical formulas are another way to represent the number of atoms. Chemical formulas are used to represent kinds of atoms in a combination. Chemical formulas use subscripts to tell how many of each atom are present in a combination. Subscripts are small numbers to the lower right of a symbol. They represent the number of atoms of that element in the equation. Before writing Chemical formulas, write down the symbol of each atom present in your equation. Writing chemical formula is a way of informing the chemical figure. It is most easily found in the periodic table. The periodic table is a chart of all well-known parts. Use the periodic table to reference the figure that cannot be remembered.