Final answer:
Two indications of a chemical change include the formation of a precipitate and an unexpected color change when two aqueous salts are mixed.
Step-by-step explanation:
When a student mixed two colorless solutions of aqueous salts at room temperature, two main indications of a chemical change are the formation of a precipitate and an unexpected color change. For example, when a precipitate forms as a result of mixing solutions, it suggests that a new substance has been created, which is insoluble in the mixture. Similarly, if the mixture changes color (from colorless to yellow, for instance), this suggests that a new substance with different properties has been formed as a result of a chemical reaction.