Charlie is balancing an equation. She has identified the atoms and counted the number of each in the reactants and products. What would Charlie adjust to make the number of atoms in the reactants the same as the number of atoms in the products?

To balance a chemical equation, Charlie adjusts the coefficients—the numbers placed in front of chemical formulas. Changing coefficients changes how many units of each substance are present, so she can make the atom counts match on both sides. Subscripts are part of a substance’s formula and should not be changed when balancing.

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