What is a compound ?

A compound is a substance formed when two or more different elements are chemically bonded together. The elements in a compound are present in fixed proportions and can only be separated by chemical means. Compounds have unique properties that are different from the elements that make them up. Examples of compounds include water (H2O), sodium chloride (NaCl), and carbon dioxide (CO2).

In chemistry, a compound is a substance that is composed of two or more different elements chemically combined in fixed proportions by mass. Compounds are formed when atoms of different elements are joined together by chemical bonds. The chemical bonds in a compound determine the properties of the compound, such as its melting point, boiling point, and reactivity. Compounds are typically classified according to their chemical composition and their chemical properties. Examples of compounds include water (H2O), carbon dioxide (CO2), and sodium chloride (NaCl).