Science Assessment

A group of campers build a fire to keep them warm and provide some light. When the wood burns, molecules that make up the wood react with oxygen in the air. This reaction results in the formation of carbon dioxide and water.

How does the chemical energy of the reactants (molecules that make up the wood and oxygen) compare to the chemical energy of the products (carbon dioxide and water) after the wood burns?

1. The chemical energy of the reactants is less than the chemical energy of the products because a chemical reaction occurred, and all chemical reactions take in energy.
2. The chemical energy of the reactants is more than the chemical energy of the products because energy was transferred from the chemical reaction as thermal energy and light.
3. The chemical energy of the reactants is more than the chemical energy of the products because a chemical reaction occurred, and all chemical reactions release energy.
4. The chemical energy of the reactants is the same as the chemical energy of the products because a chemical reaction occurred, and chemical reactions involve changes in matter not changes in energy.