Calcium carbonate decomposes on heating. The word equation for this reaction is

The decomposition of calcium carbonate upon heating is a well-known chemical reaction that can be expressed using a word equation.

1. Break Down the Problem

   • Identify the reactant: Calcium carbonate (CaCO₃).
   • Determine the products of the reaction: Calcium oxide (CaO) and carbon dioxide (CO₂).

2. Relevant Concepts

   • This is a thermal decomposition reaction where a single compound breaks down into two or more simpler products when heated.

3. Analysis and Detail

   • When calcium carbonate is heated, it undergoes thermal decomposition. The heat causes the calcium carbonate to break down into calcium oxide and carbon dioxide gas.
   • The reaction can be simplified into the equation form as follows: $\text{Calcium Carbonate (s)} \xrightarrow{\text{heat}} \text{Calcium Oxide (s)} + \text{Carbon Dioxide (g)}$

4. Verify and Summarize

   • The word equation is correct; upon heating, calcium carbonate does decompose into calcium oxide and carbon dioxide. The formation of gas (CO₂) is an indicator that a reaction has occurred.

Final Answer

The word equation for the decomposition of calcium carbonate is:
Calcium carbonate → Calcium oxide + Carbon dioxide