Question

Need help on London forces. What does it mean?

Answer 1

london dispersion forces are intermolecular forces that affect physical properties (i.e. boiling point, melting point). Molecules (or atoms), transiently, polarize one another's electron densities due to repulsion.

You can probably see, now, that this is a "chain-like" effect that causes attractions between molecules. These are the weakest of intermolecular forces though (<6 kJ/mol), in comparison to others (e.g. dipole-dipole, ionic)