A molecular dipole comes from an uneven distribution of electrons around the central atom. Although the magnitude of the bond moment will not change based on whether B is the most electronegative or the least, the direction of the bond moment will.
Figure 6 illustrates the ideal molecular structures, which are predicted based on the electron-pair geometries for various combinations of lone pairs and bonding pairs.
Chloromethane, CH3Cl, is another example of a polar molecule. Have a molecular structure such that the sum of the vectors of each bond dipole moment does not cancel.
Show Answer The molecular structure is linear. Then try to find a chemical formula that would match the structure you have drawn.
Again, there are slight deviations from the ideal because lone pairs occupy larger regions of space than do bonding electrons. The bond moments cancel because they are pointed in opposite directions. Use the electronegativity controls to determine how the molecular dipole will look for the starting bent molecule if: A and C are very electronegative and B is in the middle of the range.
Properties of Polar Molecules Polar molecules tend to align when placed in an electric field with the positive end of the molecule oriented toward the negative plate and the negative end toward the positive plate Figure