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An unknown substance undergoes a chemical change that gives off heat. What can you tell me about this substance?

User Riverfall
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on a molecular level there is a lot of movement which in turn is the reason why heat is generated.
User Mherzog
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Step-by-step explanation:

A chemical reaction in which heat is absorbed by the reactant molecules is known as an endothermic reaction.

For example,
A + B + Heat \rightarrow AB

On the other hand, a chemical reaction in which heat energy is released by the reactant molecules is known as an exothermic reaction.

For example,
A + B \rightarrow AB + Heat

Thus, we can conclude that when an unknown substance undergoes a chemical change that gives off heat then it means earlier the substance has more heat energy but after the chemical change there occurs a decrease in its heat energy because some of the heat has been released by it.

User Onur Demir
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