When sodium carbonate (Na₂CO₃) decomposes, it breaks down into two distinct products. The balanced chemical equation for this decomposition reaction is:
[tex]\[ \text{Na}_2\text{CO}_3 \rightarrow \text{Na}_2\text{O} + \text{CO}_2 \][/tex]
In this reaction, sodium carbonate decomposes to form sodium oxide (Na₂O) and carbon dioxide (CO₂). Therefore, besides sodium oxide, the other product formed is carbon dioxide.
So, in the equation:
[tex]\[ \text{Na}_2\text{CO}_3 \rightarrow \text{Na}_2\text{O} + \square \][/tex]
The correct product to fill the blank is:
[tex]\[ \text{CO}_2 \][/tex]
Thus, the complete balanced equation is:
[tex]\[ \text{Na}_2\text{CO}_3 \rightarrow \text{Na}_2\text{O} + \text{CO}_2 \][/tex]