What are products in a chemical reaction?

• A. Substances that come out of a reaction.
• B. Substances that go into a reaction.
• C. Energy released during the reaction.
• D. The catalyst used to start the reaction.

Answer: (A)

In a chemical reaction, the substances you end up with are called products. They are formed as the starting materials (reactants) transform and rearrange their atoms. Energy changes can happen, but energy itself isn’t a product—it’s the heat, light, or other energy released or absorbed during the reaction. A catalyst speeds up the reaction but isn’t consumed, so it isn’t a product either. For example, when hydrogen and oxygen react to make water, water is the product, while hydrogen and oxygen are the reactants and any energy released is not considered a product.