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.
Van der Waals' forces of attraction (also known as London dispersion forces) exist between ALL particles. It is thought that they are due to vibration of the nucleus within the negative charge cloud, creating polarity of temporary positive and negative charge within molecules.