When calcium carbonate (CaCO₃) decomposes, it breaks down into calcium oxide (CaO) and carbon dioxide (CO₂). The balanced equation for the decomposition reaction is:
\[ \text{CaCO}_3 \rightarrow \text{CaO} + \text{CO}_2 \]
So the products of the reaction are calcium oxide (CaO) and carbon dioxide (CO₂).