1. The substance has changed color: This is typically a sign that a chemical reaction has occurred, as the chemical composition of the substance has altered.
2. The substance forms a precipitate: If two clear solutions are mixed together and a solid substance forms, it indicates that a chemical reaction has taken place.
3. The substance gives off a gas: If bubbles are released when a substance is mixed with another, it indicates that a chemical reaction has occurred and a new substance has been produced.
With evidence from the text above, what are 3 different reactions that would demonstrate that a substance has undergone a chemical change?
1 answer