A bond is nonpolar if the bonded atoms have equal electronegativities. Thus there is a direct correlation between electronegativity and bond polarity. In Chapter 7 'The Periodic Table and Periodic Trends', electronegativity (χ) was defined as the ability of an atom in a molecule or an ion to attract electrons to itself. The polarity of a bond-the extent to which it is polar-is determined largely by the relative electronegativities of the bonded atoms.

Recall from Chapter 4 'Reactions in Aqueous Solution', Section 4.1 'Aqueous Solutions' that a lowercase Greek delta ( δ) is used to indicate that a bonded atom possesses a partial positive charge, indicated by δ +, or a partial negative charge, indicated by δ –, and a bond between two atoms that possess partial charges is a polar bond. Figure 8.12 'The Electron Distribution in a Nonpolar Covalent Bond, a Polar Covalent Bond, and an Ionic Bond Using Lewis Electron Structures' compares the electron distribution in a polar covalent bond with those in an ideally covalent and an ideally ionic bond. Most compounds, however, have polar covalent bonds A covalent bond in which the electrons are shared unequally between the bonded atoms., which means that electrons are shared unequally between the bonded atoms. In Chapter 2 'Molecules, Ions, and Chemical Formulas' and Section 8.1 'An Overview of Chemical Bonding', we described the two idealized extremes of chemical bonding: (1) ionic bonding-in which one or more electrons are transferred completely from one atom to another, and the resulting ions are held together by purely electrostatic forces-and (2) covalent bonding, in which electrons are shared equally between two atoms. To calculate the percent ionic character of a covalent polar bond.

Bond moment definition