covalenta

Covalenta refers to chemical bonding formed by the sharing of electron pairs between atoms. It is one of the main types of intramolecular bonds and is most common among nonmetals with similar electronegativities. When atoms share electrons, each atom can attain a more stable electron configuration, reducing overall energy.

Covalent bonds can be single, double, or triple, corresponding to one, two, or three shared pairs of electrons. The bond order affects bond length and bond energy: higher order bonds are shorter and stronger. Polarity arises when the bonded atoms have different electronegativities, leading to unequal sharing of electrons and partial charges. If the electronegativity difference is large, the bond becomes polar; if it is small, the bond is largely nonpolar. Some covalent bonds are formed by a lone pair donated from one atom to another, called coordinate (dative) bonds, and may be rearranged through resonance.

Covalent bonding leads to discrete molecules with characteristic geometries described by VSEPR theory, such as linear, trigonal planar, tetrahedral, and more complex shapes. Examples include H2 and Cl2 (nonpolar diatomic molecules); H2O, NH3, and CH4 (polar or polarizable molecules). In many materials, networks of covalent bonds form extended solids, as in diamond or silicon dioxide, which lack discrete molecules and show high hardness and high melting points.

Covalent bonds play a central role in chemistry, biology, and materials science. They determine molecular properties such as reactivity, polarity, solubility, and structural stability. They can be studied through spectroscopy, quantum chemistry calculations, and computational models.