A chemical reaction rearranges the atoms in substances that are already there. A reaction is correctly balanced when it shows us not only what is present before and after the reaction but also shows how much of each reactant and product will be present. This is called the Law of Conservation of mass.
Correct
Water formation:
1. 2 [tex]$KClO _3 \rightarrow$[/tex] 2 [tex]$KCl +$[/tex] 3 [tex]$O _2$[/tex]