2NaCO3 → 2Na + 2CO2 + O2

is a decomposition reaction.

Here's why:

* Decomposition: A single reactant (sodium carbonate, NaCO3) breaks down into multiple products (sodium, carbon dioxide, and oxygen).

* Reactants and Products: The equation shows one reactant (NaCO3) on the left side and multiple products (Na, CO2, and O2) on the right side.

Important Note: The chemical formula for sodium carbonate is Na2CO3, not NaCO3. The balanced equation for the decomposition of sodium carbonate is:

Na2CO3 → 2Na + CO2 + O2

This reaction requires a lot of energy input (heat) to occur.