Here's how it works:

* Formation: Carbon dioxide (CO₂) from the atmosphere dissolves in rainwater, forming carbonic acid.

* Reaction: Carbonic acid reacts with calcite (CaCO₃), which is the primary component of limestone, marble, and other carbonate rocks. This reaction forms calcium bicarbonate (Ca(HCO₃)₂) which is soluble in water.

* Dissolution: The calcium bicarbonate dissolves in the water, effectively dissolving the calcite.

This process is responsible for the formation of caves, sinkholes, and other karst features. It also plays a role in weathering and erosion of rocks.