Yes, that's absolutely true! When acids react with carbonates, they produce carbon dioxide gas, along with a salt and water.

Here's a simplified explanation:

* Acids contain hydrogen ions (H+) that are readily released.

* Carbonates contain the carbonate ion (CO3^2-)

* Reaction: The hydrogen ions from the acid react with the carbonate ion, forming carbonic acid (H2CO3).

* Decomposition: Carbonic acid is unstable and quickly decomposes into carbon dioxide (CO2) gas and water (H2O).

Here's a common example:

* Hydrochloric acid (HCl) + Calcium carbonate (CaCO3) → Calcium chloride (CaCl2) + Carbon dioxide (CO2) + Water (H2O)

This reaction is often used in chemistry labs to demonstrate the production of carbon dioxide. The bubbling and fizzing you see is the carbon dioxide being released.