Solid calcium carbonate is heated strongly in an open crucible. Which reaction occurs?

Core Concept

Metal carbonates characteristically decompose when heated, splitting into a metal oxide and carbon dioxide gas. Calcium carbonate follows this pattern, forming solid calcium oxide while CO₂ escapes from the open crucible, so the sample steadily loses mass. Recognizing this decomposition pattern lets you predict products for any heated metal carbonate without memorizing each salt separately.