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Which of the following examples is a sign
that a chemical change is occurring?
A. the substance seems to have disappeared
B. the state of the matter has changed
C. the production of heat, light, and smoke

Respuesta :

Answer: C. The production of heat, light and smoke

Explanation: In a chemical reaction taking place several evidence are the presence of light emission and heat is generated in the reaction. Smoke is also an indication when a chemical reaction is happening such as combustion reaction.

The answer is C. Heat is an indicator that energy is being released, which occurs during a chemical change. Light and smoke can also be factors