How do atoms form chemical bonds by lowering their total energy?

Atoms form chemical bonds to achieve a state of lower total energy, which generally results in a more stable configuration. This process is driven by the arrangement of electrons, as atoms interact to reach a more favorable electronic structure—often resembling the stable, closed-shell configuration of noble gases.1234

Atoms achieve this energy reduction through several mechanisms:

• Electron Transfer: In ionic bonding, one atom donates valence electrons to another. The resulting electrostatic attraction between the newly formed, oppositely charged ions locks them together in a lower-energy state.15
• Electron Sharing: In covalent bonds, atoms share pairs of electrons. This sharing allows atoms to attain a more stable electron configuration.16
• Metallic Bonding: In metals, outer electrons are shared collectively among all atoms, creating a stable "sea" of electrons that holds the structure together.1

While some processes, such as electron promotion, may require an initial investment of energy, they are favored if the overall formation of the molecule results in a net decrease in total energy. Ultimately, the formation of bonds is a balance of forces where the system seeks the most stable, lowest-energy arrangement possible.2164