The chemical reaction shown, 2AgCl (s) → 2Ag (s) + Cl₂ (g), is the decomposition of silver chloride into silver and chlorine gas. Silver halides like silver chloride (AgCl) and silver bromide (AgBr) are known to be sensitive to light. This decomposition reaction is catalyzed by light, particularly sunlight or bright artificial light. This property is fundamental to traditional black and white photography where silver halides in photographic film undergo decomposition upon exposure to light, forming a latent image.