While studying chemical and physical changes, students added salt to a glass of water. They stirred the salt until it dissolved and could no longer be seen. "That's a chemical change," Sarah stated. Do you agree? Explain.
I disagree with Sarah's statement that dissolving salt in water is a chemical change. Dissolving salt in water is actually a physical change because the salt molecules are still intact, they have just dispersed throughout the water. No new substances are formed during the process of dissolving salt in water. Chemical changes involve the formation of new substances with different chemical properties, which is not the case when salt dissolves in water.
