Here's why:

* Decomposition Reaction: A single reactant breaks down into two or more simpler products.

In this case:

* Reactant: Carbonic acid (H₂CO₃)

* Products: Water (H₂O) and Carbon dioxide (CO₂)

The equation representing this reaction is:

H₂CO₃ → H₂O + CO₂

Key point: This reaction is also an equilibrium reaction, meaning it can proceed in both directions. In the presence of water, carbon dioxide can react to form carbonic acid (forward reaction). However, carbonic acid is unstable and readily decomposes back into water and carbon dioxide (reverse reaction).