covalente

Covalent bonds are chemical bonds formed when two or more atoms share one or more pairs of electrons. This type of bonding typically occurs between nonmetal atoms with similar electronegativities and leads to the formation of discrete molecules rather than ionic lattices. By sharing electrons, each atom can attain a more stable electron configuration, often resembling a noble-gas arrangement.

Single, double, and triple covalent bonds indicate the number of shared electron pairs: one pair for a single bond, two for a double bond, and three for a triple bond. Bond strength generally increases with more shared pairs, and bond length decreases as the number of shared electrons grows. Polarity arises when electronegativities differ, producing polar covalent bonds with partial charges; when the difference is small, the bond is considered nonpolar covalent.

Hybridization of atomic orbitals (for example sp3, sp2, sp) and VSEPR theory help explain molecular geometries such as tetrahedral, trigonal planar, and linear shapes. Some covalent interactions are coordinate (donor-acceptor) bonds, where both electrons come from one atom but are shared in the bond.

Covalent structures range from simple diatomic molecules (H2, O2) to complex organic compounds (methane, benzene) and covalent network solids (diamond, graphite, silicon dioxide). In water, the O–H bonds are polar covalent, contributing to water’s dipole moment and many of its properties. Compared with ionic bonds, covalent bonds involve electron sharing rather than complete electron transfer, which influences solubility, melting points, and electrical conductivity in different environments.