When aluminum carbonate (Al₂(CO₃)₃) is heated, it decomposes into aluminum oxide (Al₂O₃), carbon dioxide (CO₂) gas, and water (H₂O) vapor. This reaction is a typical example of a thermal decomposition reaction.

Here's the balanced chemical equation for the reaction:

Al₂(CO₃)₃ (s) → Al₂O₃ (s) + 3 CO₂ (g) + 3 H₂O (g)

Explanation:

* The aluminum carbonate solid breaks down into its constituent elements, forming aluminum oxide, carbon dioxide, and water.

* The carbon dioxide and water are released as gases, making the reaction irreversible.

* This decomposition typically occurs at high temperatures.

Important Note: The water molecule in the decomposition product is formed because aluminum carbonate usually contains some water of hydration.