1 Raised over Fort McHenry on the morning of September 14, 1814, to signal American victory over the British in the Battle of Baltimore; the sight inspired Francis Scott Key to write The Star-Spangled Banner. 2  Preserved by the Armistead family as a memento of the battle.
London dispersion forces are a type of intermolecular force. They are relatively weak. They are also called induce-dipole induce-dipole interactions. 1  Present in non-polar molecules.  Due to non-systematic electron distribution where one molecule induces a dipole on another molecule.
The intermolecular forces of attraction considered here are: Van der Waals' forces; permanent dipole-permanent dipole interactions; hydrogen bonding; Van der Waals' forces. Van der Waals' forces are forces of attraction which exist between all atoms and molecules. Van der Waals' forces are much weaker than all other types of bonding. They are only significant in atoms and molecules which have no other types of intermolecular forces of attraction, for example, discrete non-polar molecules and the Group 0 elements.