chemicalbond

A chemical bond is a lasting attraction between atoms that enables the formation of chemical compounds. It arises from interactions among electrons and nuclei, typically through electron sharing or electron transfer, which leads to configurations that are more stable than separate atoms.

The main types are ionic, covalent, and metallic bonds. Ionic bonds form when electrons are transferred from one atom to another, creating ions held together by electrostatic attraction, as seen in table salt (NaCl). Covalent bonds involve sharing one or more pairs of electrons between atoms; they can be nonpolar or polar depending on the difference in electronegativity. Covalent bonds also vary in bond order, producing single, double, or triple bonds. Metallic bonds consist of a lattice of positively charged ions surrounded by a sea of delocalized electrons, which accounts for many characteristic properties of metals. A coordinate (dative) bond is a covalent bond in which both electrons come from the same atom.

Non-covalent interactions, such as hydrogen bonds and van der Waals forces, influence the properties and behavior of substances but are not considered true covalent or ionic bonds. Delocalized bonding and resonance describe situations where electrons are shared across multiple atoms, altering bond character and stability.

Theoretical approaches include valence bond theory, which emphasizes orbital overlap and hybridization, and molecular orbital theory, which describes bonding with molecular orbitals extending over a molecule. Bond strength and length correlate with bond energy and bond order: higher bond order usually means shorter, stronger bonds. Bonding also determines polarity, reactivity, and many physical properties of substances, playing a central role in chemistry and materials science.