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.
Thus, they are called intermolecular forces. There are three main types of secondary bonds: dipole-dipole, London dispersion and hydrogen bonds. Hydrogen bond is a special type of dipole-dipole attraction that occurs between a lone pair of electrons on an electronegative atom and a hydrogen atom in a polar bond. The main difference between dipole-dipole and London dispersion forces is that dipole-dipole forces occur among molecules with dipole moment whereas London dispersions occur due to instantaneous dipoles that form in atoms or nonpolar molecules. This article explains, 1.