Factors that affects the strength of a dispersion force
• #"Distance between molecules."# Molecules must be very close together for these attractive forces to occur.
• #"Polarizability"# which is the ease with which an electron cloud can be deformed - larger molecules have greater number of electrons and therefore are more polarizable. This leads to stronger London dispersion forces.
• #"Shape of the molecule. "#The shape of the molecule (3-Dshape) affects the area available for interaction with neighboring molecules. The larger the surface area, the greater the dispersion forces. London dispersion forces between spherical molecules are smaller than those between more cylindrically shaped molecules and this is reflected in their boiling points. (e.g. pentane b.p 309.4 K and neopentane b.p 282.7.4 K).
