Texas A&M University (TAMU) CHEM107 General Chemistry for Engineering Students Exam 2 Practice

A polar covalent bond forms between two nonmetals that have a significant difference in electronegativity. In this scenario, one nonmetal atom attracts the shared electrons more strongly than the other due to its higher electronegativity. This unequal sharing of electrons leads to the development of partial positive and negative charges on the atoms, creating a dipole moment in the molecule. The greater the difference in electronegativity, the more polarized the bond becomes.

In distinction to other bond types, a nonpolar covalent bond occurs between nonmetals with similar electronegativities, where electrons are shared equally. An ionic bond typically forms between a metal and a nonmetal, resulting from the complete transfer of electrons, rather than sharing. Metallic bonds involve the pooling of electrons among many metal atoms, contributing to properties like conductivity and malleability. Understanding these distinctions helps in recognizing why polar covalent bonds emerge from nonmetals with notable electronegativity differences.