Question

Write the states of the compounds in balanced equation for
CaCO3 + ∆ ===> CaO + CO2

Answer 1

ANSWER:-

Ca(CO)3 (s) => CaO (s) + CO2 (g).

A decomposition reaction is one where by the single reactant breaks down into two or more elements or new compounds.

If you can see, this reaction involves one compound (Ca(CO)3), breaking down into two compounds (CaO and Co2), thus fulfilling the criteria shown above.