Polarity of BondsMolecular Polarity

Equal Pull on ElectronsIf there is no difference in the electronegativity of the atoms forming a covalent bond, it forms a non-polar covalent bond.

Bonded electrons are shared equally between the two atoms.

Unequal Pull on ElectronsIf there is a difference in the electronegativity of the atoms forming a covalent bond, it forms a polar covalent bond.

Expressing Polar BondsPolar bonds are represented visually by bond dipoles.

The dipole shows the direction of the more negative charge density and the strength of the dipole.

Electron DensityThe atom with the higher electronegativity will hold the electrons in the bond more often and has a partial negative charge.

Nonpolar MoleculesBinary molecules with a nonpolar bond do not have a molecular dipole.Molecules with polar

bonds can be nonpolar if the dipoles are of equal strength and in cancelling directions.

Polar MoleculesPolar molecules are affected by electrical fields and have electrostatic interactions with other molecules. POSITIVE

FIELDNEGATIVEFIELD

Polarity Practice1) True or False: The molecule below has no bond dipole.

Polarity Practice2) True or False: The molecule below has no bond dipole.

Polarity Practice3) True or False: The molecule below is polar.

Polarity Practice4) True or False: This molecule contains bond dipoles and has a molecular dipole.

Polarity Practice5) True or False: This molecule contains bond dipoles and has a molecular dipole.

Polarity Practice6) True or False: This molecule contains bond dipoles and has a molecular dipole.

Polarity Practice7) True or False: This molecule contains bond dipoles but has no molecular dipole.

Polarity Practice8) True or False: This molecule contains bond dipoles but has no molecular dipole.