Signs that a chemical reaction have taken place:
- a new substance has been created
- formation of a gas
- formation of a solid
- release of energy
A burning fire is a common example of a chemical reaction. As the wood is set on fire, it undergoes a chemical change. When it is done burning it is ash, a new substance with a different chemical structure.
A burning fire is an example of an exothermic and an endothermic reaction. Fire releases heat into its surroundings, making it exothermic, but the wood takes in the heat to burn, making it endothermic.
Parts of a Chemical Reaction
Reactant - a substance that participates in a chemical reaction, such as isooctane.
Product - a substance that forms in a chemical reaction, like CO2 and H2O form when isooctane is burned.