Decomposition reactions require energy either in the form of heat, light, or electricity for breaking down the reactants. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light, and electricity.

(1) Decomposition on heating: Calcium carbonate when heated gives quicklime (CaO) and carbon dioxide
CaCO₃ → CaO + CO₂
(2) Decomposition by light: Silver chloride decomposes to silver and chlorine in presence of sunlight
2AgCl → 2Ag + Cl₂
(3) Decomposition by electricity: Water on electrolysis gives hydrogen and oxygen
2H₂O → 2H₂ + O₂