When a substance is heated, it gains thermal energy. Therefore, its particles move faster and its temperature rises. When a substance is cooled, it loses thermal energy, which causes its particles to move more slowly and its temperature to drop.
Answer:
Exposure of silver chloride to sunlight for a long duration turns grey due to photolytic decomposition i.e decomposition in the presence of sunlight.
Explanation:
When silver chloride, AgCl is exposed to sunlight for a long time, it will undergo decomposition as the sunlight provides sufficient energy needed to decomposed the salt, AgCl to metallic silver and chlorine gas. This can be seen in the equation below:
2AgCl —> 2Ag + Cl2
