Final answer:
When ammonium chloride crystals are dissolved in water, the temperature of the water decreases. This indicates an endothermic process, meaning that energy is absorbed from the surroundings.
Step-by-step explanation:
When ammonium chloride crystals are dissolved in water, the temperature of the water decreases. This indicates an endothermic process, meaning that energy is absorbed from the surroundings. In this case, the dissolution of ammonium chloride is an example of an endothermic reaction. The energy needed to break the bonds between the ammonium chloride ions is greater than the energy released when the ions are attracted to the water molecules. As a result, the temperature of the water decreases.