Molecules
Molecules are the basic building blocks of compounds. They consist of atoms that are connected by chemical bonds. Molecules can contain one or more atoms of the same or different chemical elements.
Atoms are joined in molecules by chemical bonds such as covalent bonds or ionic bonds. Covalent bonds create molecules in which atoms share electrons, while ionic bonds create molecules composed of oppositely charged ions.
Molecules can differ in their chemical composition, structure and physical properties. Different molecules can have different functions and purposes. For example, water is a molecule that is composed of two hydrogen atoms and one oxygen atom (H2O). Other molecules can form substances such as sugars, proteins, fats, acids and many others.
Molecules are the basis of chemistry and are studied not only in terms of their structure, but also in terms of their reactions, properties and interactions with other molecules.