Determine which elements are balanced and unbalanced for each chemical equation below when every compound is given a coefficient of one.

H2 + O2 ---> H2O The hydrogen are balanced, but the oxygens are not. We have to get both balanced. We put a two in front of the water and this balances the oxygen. H2 + O2 ---> 2H2O However, this causes the hydrogen to become unbalanced. To fix this, we place a two in front of the hydrogen on the left side. 2H2 + O2 ---> 2H2O This balances the equation.