Write a balanced chemical equation, including physical state symbols, for the decomposition of solid calcium carbonate (CaCO_3) into solid calcium oxide and gaseous carbon dioxide.

CaCO₃(s) → CaO(s) + CO₂(g)

Explanation:

The decomposition reaction always make two compounds from one.

The products always have simpler chemical structure, originated from a determined compound. This can happens  spontaneously or by a third party.

A notable example of decomposition is hydrolysis. As for example the case of water, which decomposes and generates oxygen and hydrogen gas

2H₂O (l) → 2 H₂ (g) + O₂ (g)

In this case, the calium carbonate decomposes into CaO and CO₂

These two, are the products of the decomposition.

Of course, the unique reactant is the Calcium Carbonate

The balanced equation is:

CaCO₃(s) → CaO(s) + CO₂(g)

CaCO3(s) → CaO(s) + CO2(g)

Explanation:

Step 1: Data given

Solid calcium carbonate = CaCO3(s)

solid calcium oxide = CaO(s)

gaseous carbon oxide = CO2(g)

Step 2: The unbalanced equation

CaCO3(s) → CaO(s) + CO2(g)

This equation is already balanced. We don't have to balance anything.

The balanced equation is:

CaCO3(s) → CaO(s) + CO2(g)

a is the correct answer