Is 2CaO 3CO2 2CaCO3 a combination reaction?

Yes, the reaction ( 2\text{CaO} + 3\text{CO}_2 \rightarrow 2\text{CaCO}_3 ) is a combination reaction. In this process, calcium oxide (CaO) and carbon dioxide (CO₂) combine to form calcium carbonate (CaCO₃). Combination reactions involve two or more reactants forming a single product, which is exactly what occurs here.