Answer:
C. a change in the total mass of the product
Explanation:
A chemical reaction is a reaction that alters the chemical composition of the substances involved. Based on the options in this question, a chemical reaction possess the following features:
- The atoms of the substance called reactants are rearranged into products but the total number of atoms remain the same after the reaction.
- A change in odor occurs as one of the indicators that a chemical reaction has taken place.
- Energy is either absorbed (endothermic) or released (exothermic) in the chemical reaction.
However, one untrue option is that "there is a change in the total mass of the product". The total mass of a chemical reaction does not change i.e. remains the same, before or after the reaction in accordance to the law of conservation of mass.