Answer: A reaction in which one compound breaks into two or more simpler substances; \(\mathrm{C_{12}H_{22}O_{11} \xrightarrow{\Delta} 12C + 11H_2O}\).
In a decomposition reaction a single reactant breaks down into two or more simpler products, usually when heat, light or electricity is supplied.
On strong heating, sugar (sucrose) decomposes into carbon (black residue) and water vapour:
\[\mathrm{C_{12}H_{22}O_{11} \xrightarrow{\text{heat}} 12C + 11H_2O}\]