Final answer:
A change in color, gas production, formation of precipitate, and energy transfer are indicators of a chemical reaction, including exothermic reactions.
Step-by-step explanation:
There are four visual clues that indicate that a chemical reaction is likely occurring:
- A change of color occurs during the reaction.
- A gas is produced during the reaction.
- A solid product called a precipitate is produced in the reaction.
- A transfer of energy occurs as a result of the reaction.
These factors can help recognize that an exothermic reaction has occurred.