1. IM/VdW forces are the forces of attraction between molecules – not within the molecule. VdW forces vary in strength depending on the interactions between molecules.

2. Polar molecules act as tiny “dipoles” (equal & opposite charges separated by short distances) Dipole – dipole forces attract between molecules such as between two water molecules. Positive H region is attracted to negative O region of a different molecule.

3. attracted to (like a magnet) Electrons of one atom are attracted to another atom’s nucleus  

4. O HH N H H H C COO Al Cl S HH

5. In hydrogen bonding, a hydrogen atom is attracted to an unshared pair of electrons of an –OH, -NH, or –FH group.

6. Surface Tension Enhancement of the intermolecular attractive forces at the surface

7. The cohesive forces between molecules are shared with all neighboring atoms. Since the surface has no neighboring atoms above, they exhibit stronger attractive forces for their neighbors next to and below them

8. Surface tension is a result of cohesive intermolecular forces

9. Soap breaks the surface tension!