When atoms are stable what do they form?

When atoms are stable, they tend to form molecules or compounds by bonding with other atoms. This stability often arises when atoms achieve a full outer electron shell, typically through covalent or ionic bonding. The resulting structures can range from simple diatomic molecules to complex macromolecules, depending on the types of atoms involved and their interactions. Ultimately, stable atoms contribute to the diverse array of substances that make up matter.