What is formed when two or more atoms join chemically?

When two or more atoms bond together through chemical links, they form a molecule. Molecules can consist of the same type of atom, such as in diatomic molecules like oxygen (O2), or different types of atoms, leading to the formation of compounds. In chemistry, a molecule represents the smallest fundamental unit of a chemical compound that retains its chemical properties.

In contrast, a mixture refers to a physical combination of substances that can be separated by physical means and does not involve chemical bonding. A solution is a specific type of mixture where one substance (the solute) dissolves in another (the solvent), resulting in a homogeneous mixture, but again, this does not imply that any new chemical entities are formed. A compound, while sometimes used interchangeably with a molecule in casual conversation, specifically refers to a substance formed when two or more different elements chemically bond together. Therefore, while a compound is indeed a type of molecule, the more general term that encompasses both is simply a molecule.