Why do sinkholes suddenly appear?

Answer: Underground limestone dissolves

Underground limestone dissolves ✓ — Correct! Sinkholes form when acidic groundwater slowly dissolves underground limestone (calcium carbonate), creating cavities. The surface appears normal until the cavity grows too large—then the ground suddenly collapses! Heavy rain, droughts changing water tables, or human activity can trigger collapse. Florida has frequent sinkholes due to limestone bedrock!

Tree roots push ground upward — Wrong. Tree roots don't cause sinkholes—they grow in soil near the surface, not deep enough to affect bedrock. Sinkholes form when acidic water dissolves underground limestone, creating cavities that eventually collapse.

Tree roots break up ground — Wrong. Tree roots don't cause sinkholes. These form from chemical weathering of bedrock, not biological processes.