What do carbonates produce when decomposed?
The thermal decomposition of metal carbonates produces metal oxides and carbon dioxide.
CaCO₃ → CaO + CO₂
CuCO₃ → CuO + CO₂
It takes a lot of energy to decompose the carbonates of metals that are high in the reactivity series (such as sodium and magnesium). In fact, most of the Group 1 metal carbonates do not decompose at the temperatures reached by a Bunsen burner.