The correct answer is True.
Step-by-step explanation
Chemical reactions are processes in which two or more chemical substances are involved, known as reactants or reagents, as a product of these reactions the matter of the initial substances is transformed into a new substance. In chemical reactions, the elements undergo a profound transformation that changes their structure and molecular composition. In general, chemical reactions have physical indicators, that is, a manifestation that allows knowing that a chemical reaction is happening such as a color change, temperature change, change of state (solid, liquid or gas), density change, between others. So, the correct answer is True, because a release of heat is a change in temperature which means that a chemical reaction is occurring.