Which factor is NOT a characteristic of a chemical reaction?

The correct answer highlights that the creation of energy without any reactants is not a characteristic of a chemical reaction. In a typical chemical reaction, energy is either absorbed or released as reactants are transformed into products, but this process always involves the existing reactants.

Chemical reactions are fundamentally characterized by the formation of new substances, which occurs as bonds between atoms are broken and new bonds are formed. This results in the rearrangement of atoms, which is a core aspect of the reaction process. Changes in the state of matter, such as from solid to liquid or liquid to gas, can accompany many chemical reactions but are not a requirement for all reactions to occur.

The option concerning the creation of energy implies a scenario where energy is produced without any reactants, which does not align with the principles of chemistry. Energy must come from the reactants or the process itself in any chemical reaction, reinforcing the idea that all changes must involve matter.