A chemical reaction occurs when one or more substances (reactants) are rearranged to form new and different substances (products).
Chemical reactions can be categorized into synthesis, decomposition, combustion, single replacement, and double replacement. We use a chemical equation when a chemical reaction needs to be represented.
An example of a chemical reaction we can see every day in many materials is the formation of iron oxide. This reaction is called an oxidation reaction, which occurs when oxygen from the air comes into contact with iron.
