Bond Polarity

electronegativity

power of an atom to attract the pair of electrons in a covalent bond

electron distribution in a covalent bond between elements with different electronegativities =

unsymmetrical

• produces a polar covalent bond

• may cause → permanent dipole

electronegativity factors:

-size

-nuclear charge

electronegativity trends:

-increases along a period (as atomic radius decreases)

-decreases down a group (as shielding increases)

polar bond →

when two atoms bonded have different electronegativities

more electronegative an atom is =

draws more of the negative charge towards itself, producing a - region and + region

• permanent dipole

polar molecules with a permanent dipole aligned can form →

lattice of molecules (similar to ionic lattice)

induced dipole

-form when electron orbitals around a molecule are influenced by another charged particle