Chemistry is the study of matter, its properties, how and why substances combine or separate to form other substances, and how substances interact with energy. A chemical is any substance consisting of matter. This includes any liquid, solid, or gas.
Chemicals can be classified into different categories based on their composition and properties:
Chemical reactions occur when substances undergo chemical changes to form new substances. These reactions involve the breaking and forming of chemical bonds. The reactants are the substances that participate in the reaction, while the products are the substances formed as a result of the reaction.