Once we have identified all the reactants and products and have written the correct
formulas for them, we assemble them in the conventional sequence—reactants
on the left separated by an arrow from products on the right. The equation written at
this point is likely to be unbalanced; that is, the number of each type of atom on one
side of the arrow differs from the number on the other side. In general, we can balance
a chemical equation by the following steps