Question

physical vs. chemical change quick check
why is it difficult to classify dissolving as simply a physical or a chemical change? (1 point)
some substances taste the same after they dissolve, and others do not.
some substances keep the same color when they dissolve, and others do not.
some substances release energy when they dissolve, and some absorb energy
some substances keep the same molecular structure when they break down, and others do not.

Explanation:

Physical changes involve no change in molecular structure, while chemical changes do. In dissolving, some substances maintain their molecular structure (physical - like sugar in water), while others react with the solvent and change their molecular structure (chemical - like some metal salts in water). So, the key factor is the molecular - structure change during dissolving.

Answer:

Some substances keep the same molecular structure when they break down, and others do not.