What is a bond dipole?

Similarly, dipole-dipole forces are those of attraction between polar molecules, and polar molecules only. In this rule noble gases are ignored. F O N Cl are polar.

A bond dipole is when one atom in a bond has a greater electronegativity than the other atom in the bond. Therefore it has a greater pull on the electrons in the bond causing a charge separation. As a result that atom would appear to be slightly negative as the electrons are closer to it and the other would appear slightly positive as the electrons are farther away. As a result there is a charge separation and therefore a dipole.