Which of the following accurately describes energy conservation in chemical changes?

Energy conservation in chemical changes is best described by the principle that energy can only change forms but is always conserved. This principle stems from the law of conservation of energy, which states that in any chemical reaction or physical process, the total energy in a closed system remains constant.

In the context of a chemical reaction, the energy present in the reactants can be transformed into different forms, such as thermal energy (heat), light energy, or chemical energy in the products. For instance, during combustion, the chemical energy stored in the reactants is converted into heat and light energy, but no energy is lost; it has simply changed from one form to another.

This understanding underscores the importance of energy transformations in chemical processes and helps predict how energy will interact in reactions, making option C the accurate choice.