Ammonium carbonate does not exist as a stable compound. It readily decomposes into ammonia (NH₃), carbon dioxide (CO₂), and water (H₂O).

However, if you're referring to the decomposition reaction of ammonium carbonate, here's the balanced equation:

(NH₄)₂CO₃(s) → 2NH₃(g) + CO₂(g) + H₂O(g)

This equation shows that solid ammonium carbonate decomposes into gaseous ammonia, carbon dioxide, and water.