A chemical reaction is the process that changes one set of chemicals into another. Chemical reactions rearrange the atoms of the reactants to form different substances or products.
Chemical reactions happen all the time, and they make life, society, culture and technology possible. Some examples of everyday chemical reactions include burning fossil fuels, making glass and brewing beer. Chemical reactions occur in all living things, including the geology of Earth, the oceans and the environment.
The idea of chemical reactions has been around for about 250 years. It has its origins in early experiments and theories of elements and compounds.