Question

from the text: what is the third step in balancing chemical equations?
steps to balance chemical equation using hit and trial method
in the above - balanced equation, there is one atom of carbon and four atoms of hydrogen on both sides of the arrow. below are guidelines for writing and balancing chemical equations.

1. determine the correct chemical formulas for each reactant and product.
2. write the skeleton equation.
3. count the number of atoms of each element that appears as a reactant and as a product. if a polyatomic ion is unchanged on both sides of the equation, count it as a unit.
4. balance each element one at a time by placing coefficients in front of the formulas.
5. it is best to begin by balancing elements that only appear in one formula on each side of the equation.
6. no coefficient is written for 1. this means that the coefficient is written only when its value is greater than 1.
7. never change the subscripts in a chemical formula as it will change the ratio of atoms in reactants and products leading to a change in their chemical properties. therefore, you can only balance equations by using coefficients.
8. check each atom or polyatomic ion to be sure that they are equal on both sides of the equation.
9. make sure that all coefficients are in the lowest possible ratio. if necessary, reduce to the lowest ratio.

Explanation:

The text clearly lists the steps for balancing chemical equations. The third step is explicitly stated as counting the number of atoms of each element (or polyatomic ion as a unit if unchanged) on both sides of the equation.

Answer:

Count the number of atoms of each element that appears as a reactant and as a product. If a polyatomic ion is unchanged on both sides of the equation, count it as a unit.