What role do valence electrons play in Gilbert N. Lewis's model of chemical bonding?

In Gilbert N. Lewis’s model of chemical bonding, valence electrons are the primary participants in forming bonds between atoms. Lewis proposed that atoms interact to achieve a stable electronic configuration, typically resembling that of the nearest noble gas in the periodic table.123

His model distinguishes between two primary types of bonding based on the behavior of these electrons:

• Ionic Bonds: Lewis proposed that these form through the complete transfer of valence electrons from one atom to another, resulting in the formation of charged ions.2
• Covalent Bonds: Lewis introduced the concept that a covalent bond consists of a pair of electrons shared between two atoms. This sharing allows each atom to effectively possess a stable, closed-shell configuration.423

To represent these electronic structures, Lewis introduced Lewis structures, which use dots to symbolize valence electrons around an element's chemical symbol. His approach is summarized by the octet rule, which states that atoms tend to gain, lose, or share electrons until they are surrounded by an octet—eight electrons—in their valence shell.412