Define chemical.

A chemical is a substance that is composed of atoms and molecules, and has a specific composition and properties. Chemicals can be found in various forms, such as solids, liquids, or gases, and can undergo chemical reactions to form new substances. They are used in a wide range of applications, including industry, agriculture, medicine, and everyday household products.

A chemical is a substance that has a specific composition and structure composed of atoms, molecules, or ions. Chemicals can be found in a wide variety of forms, including solids, liquids, and gases. They can be natural or synthetic, and they can be used for a variety of purposes, such as cleaning, cooking, and manufacturing.