Sigma bond

A sigma bond is a type of strong chemical bond formed when two atoms share electrons directly between their nuclei, resulting in a stable connection. It occurs when the overlapping of atomic orbitals creates a region of increased electron density along the line connecting the two nuclei. This direct overlap provides the primary bonding interaction in many molecules, such as single bonds in H₂ or CH₄. Sigma bonds are characterized by their symmetry and strength, and they serve as the foundational bonds through which atoms hold together in molecular structures.