How are Lewis dot diagrams used to show the electrons in atoms and molecules?

Lewis dot diagrams, introduced by the American chemist Gilbert N. Lewis, are a conventional method for representing the electronic structure of atoms and molecules.12

Representing Atoms and Molecules

• Valence Electrons: Lewis represented valence electrons—the electrons in the outer shell that participate in bonding—as dots arranged around the chemical symbol of an element.1
• Covalent Bonds: In molecules, a covalent bond is represented as a shared pair of electrons. In modern diagrams, this shared pair is typically depicted as a line (dash) between atoms, while unshared electrons are shown as dots called lone pairs.34
• The Octet Rule: These diagrams are used to illustrate how atoms achieve a stable configuration, often by attaining a full outer shell of eight electrons, known as the octet rule.53

While these structures effectively show the topological pattern of bonds, they do not necessarily represent the actual three-dimensional shape of a molecule.34